If I were you I'd cross post to 28MM fantasy if you haven't already as it is more likely that people there could help you out.
I doubt very much that there will be an issue, but for future reference: "collectible miniature games" in the board title generally refers more to plastic pre-painted, sometimes "clicky" figures that are often sold in blind packs rather than hard to find or out of print metal miniatures or kits.
Examples are lines like the the D&D figures, Dreamblade, Starwars, Heroclix, Mageknight, Halo Clix, Mechwarrior Clix, Monsterpocalypse, etc. Usually the focus is on either collecting and trading figures in current blind pack lines or on finding supplies of defunct lines that are being sold off for a nickel a pound as cheap ways to fill out a 28mm sci-fi or fantasy army or to get stuff together for a dungeon crawl.
I have seen some similar things mentioned like Gashapon (capsule toys usually related to popular anime)and blind-boxed vinyl collector figures brought up here even though they have no game associated with them.
Sometimes people want to know about non-collectible plastic Heroscape playset type figures that are sold in packs of multiple figures that are sold like toys where evtrything is visible and there is no variation in a package.
Occasionally someone will mention Robostrux/Zoids, or things that might really be closer to toy gaming.
AT-43, Dust tactics, and the plastic Confrontation line are sometimes brought up as well even though they are not exactly collectible they ARE pre-paints so the interest coincides.
Cheers! Hope you find what you are after.