diff --git a/include/xo/gc/CollectorTypeRegistry.hpp b/include/xo/gc/CollectorTypeRegistry.hpp
deleted file mode 100644
index 4474e20..0000000
--- a/include/xo/gc/CollectorTypeRegistry.hpp
+++ /dev/null
@@ -1,74 +0,0 @@
-/** @file CollectorTypeRegistry.hpp
- *
- *  @brief Runtime type registration for gc-aware types
- *
- *  @author Roland Conybeare, Jan 2026
- **/
-
-#pragma once
-
-#include "Collector.hpp"
-#include <functional>
-
-namespace xo {
-    namespace mm {
-        /** @class CollectorTypeRegistry
-         *
-         *  @brief Runtime registry for gc-aware types
-         *
-         *  Singleton to remember known gc-aware types;
-         *  use to simplify registering such types
-         *  with a collector instance.
-         *
-         *  Remark: splitting work here between
-         *  1. static initializer work: tracking gc-aware types,
-         *  2. runtime post-configuration work: report
-         *     gc-aware types to GC instances
-         *
-         *  Use:
-         *  1. subsystem foo provides function foo_register_types(obj<ACollector> gc)
-         *     Function calls
-         *       gc.install_type(impl_for<AGCObject, DQuux>())
-         *     for each gc-aware type provided by subsystem foo
-         *
-         *     Example: in file xo-object2/src/object2/object2_register_types.cpp, see
-         *       object2_register_types()
-         *
-         *  2. during subsystem init, call
-         *       CollectorTypeRegistry::instance().register_types(&foo_register_types);
-         *
-         *     Example: in file xo-object2/src/object2/init_object2.cpp, see
-         *       InitSubsys<S_object2_tag>::init()
-         *
-         *  3. during Collector setup, call
-         *       obj<ACollector> gc = ...;
-         *       CollectorTypeRegistry::instance().install_types(gc);
-         *
-         *    Example: in file xo-object2/utest/X1Collector.test.cpp
-         *       TEST_CASE("x1")
-         **/
-        class CollectorTypeRegistry {
-        public:
-            using init_function_type = std::function<bool (obj<ACollector>)>;
-
-        public:
-            /** singleton instance **/
-            static CollectorTypeRegistry & instance();
-
-            /** remember a gc-aware type-registration function **/
-            void register_types(init_function_type init_fn);
-
-            /** register known GC-aware types with @p gc.
-             *  Calls @c gc.isntall_type() for each
-             *  such type.
-             **/
-            bool install_types(obj<ACollector> gc);
-
-        private:
-            /** initialization steps for a new Collector instance **/
-            std::vector<init_function_type> init_seq_v_;
-        };
-    }
-}
-
-/* end CollectorTypeRegistry.hpp */
diff --git a/src/gc/CMakeLists.txt b/src/gc/CMakeLists.txt
index 985592b..6690932 100644
--- a/src/gc/CMakeLists.txt
+++ b/src/gc/CMakeLists.txt
@@ -3,11 +3,6 @@
 set(SELF_LIB xo_gc)
 set(SELF_SRCS
 
-    CollectorTypeRegistry.cpp
-
-    ICollector_Any.cpp
-    IGCObject_Any.cpp
-
     IAllocator_DX1Collector.cpp
     ICollector_DX1Collector.cpp
     IAllocIterator_DX1CollectorIterator.cpp
diff --git a/src/gc/CollectorTypeRegistry.cpp b/src/gc/CollectorTypeRegistry.cpp
deleted file mode 100644
index cb039dd..0000000
--- a/src/gc/CollectorTypeRegistry.cpp
+++ /dev/null
@@ -1,45 +0,0 @@
-/** @file CollectorTypeRegistry.cpp
- **/
-
-#include "CollectorTypeRegistry.hpp"
-#include <xo/indentlog/scope.hpp>
-
-namespace xo {
-    namespace mm {
-        CollectorTypeRegistry &
-        CollectorTypeRegistry::instance() {
-            static CollectorTypeRegistry s_instance;
-
-            return s_instance;
-        }
-
-        void
-        CollectorTypeRegistry::register_types(init_function_type fn) {
-            scope log(XO_DEBUG(true));
-
-            init_seq_v_.push_back(fn);
-        }
-
-        bool
-        CollectorTypeRegistry::install_types(obj<ACollector> gc) {
-            scope log(XO_DEBUG(true));
-
-            bool ok = true;
-
-            size_t i = 0;
-            size_t n = init_seq_v_.size();
-            log && log("run n init steps", xtag("n", n));
-
-            for (const auto & fn : init_seq_v_) {
-                log && log("do install fn (", i+1, "/", n, ")");
-
-                ok = ok & fn(gc);
-            }
-
-            return ok;
-        }
-
-    } /*namespace mm*/
-} /*namespace xo*/
-
-/* end CollectorTypeRegistry.cpp */
diff --git a/src/gc/ICollector_Any.cpp b/src/gc/ICollector_Any.cpp
deleted file mode 100644
index b39aa99..0000000
--- a/src/gc/ICollector_Any.cpp
+++ /dev/null
@@ -1,40 +0,0 @@
-/** @file ICollector_Any.cpp
- *
- *  @author Roland Conybeare, Dec 2025
- **/
-
-#include "gc/ICollector_Any.hpp"
-#include <iostream>
-#include <exception>
-
-namespace xo {
-    using xo::facet::DVariantPlaceholder;
-    using xo::facet::typeseq;
-    using xo::facet::valid_facet_implementation;
-
-    namespace mm {
-
-        void
-        ICollector_Any::_fatal() {
-            /* control here on uninitialized ICollector_Any.
-             * Initialized instance will have specific implementation type
-             * e.g. ICollector_Xfer<DCollector>
-             */
-
-            std::cerr << "fatal"
-                      << ": attempt to call uninitialized"
-                      << " ICollector_Any method"
-                      << std::endl;
-            std::terminate();
-        }
-
-        typeseq
-        ICollector_Any::s_typeseq = typeseq::id<DVariantPlaceholder>();
-
-        bool
-        ICollector_Any::_valid = valid_facet_implementation<ACollector, ICollector_Any>();
-
-    } /*namespace mm*/
-} /*namespace xo*/
-
-/** end ICollector_Any.cpp */
diff --git a/src/gc/IGCObject_Any.cpp b/src/gc/IGCObject_Any.cpp
deleted file mode 100644
index 10ff8f6..0000000
--- a/src/gc/IGCObject_Any.cpp
+++ /dev/null
@@ -1,48 +0,0 @@
-/** @file IGCObject_Any.cpp
- *
- **/
-
-#include "gc/IGCObject_Any.hpp"
-#include <iostream>
-#include <exception>
-
-namespace xo {
-namespace mm {
-
-using xo::facet::DVariantPlaceholder;
-using xo::facet::typeseq;
-using xo::facet::valid_facet_implementation;
-
-void
-IGCObject_Any::_fatal()
-{
-    /* control here on uninitialized IAllocator_Any.
-     * Initialized instance will have specific implementation type
-     */
-    std::cerr << "fatal"
-              << ": attempt to call uninitialized"
-              << " IGCObject_Any method"
-              << std::endl;
-    std::terminate();
-}
-
-typeseq
-IGCObject_Any::s_typeseq = typeseq::id<DVariantPlaceholder>();
-
-bool
-IGCObject_Any::_valid
-  = valid_facet_implementation<AGCObject, IGCObject_Any>();
-
-// nonconst methods
-
-auto
-IGCObject_Any::forward_children(Opaque, obj<ACollector>)  const  noexcept -> size_type
-{
-    _fatal();
-}
-
-
-} /*namespace mm*/
-} /*namespace xo*/
-
-/* end IGCObject_Any.cpp */