US Cartridge belt. I've been following the same search for about a month now. Most examples are complete belts of various dates and condition but occasionally half a belt or parts come up. It's not instantaneous always but eventually almost everything you seek will show up. I've been watching for some rifle parts for years so patience is a real virtue. I'm currently after WWI belts, just got a complete dismounted belt two weeks ago. Now watching for a nice mounted belt. I check the WWII stuff occasionally just to see what's there.