I've fired the fiocchi 7.63 mauser rounds out of both the 10 rounders with no hiccups. The 7.63 mauser cartridge was one of the highest velocity pistol cartridges until .357 magnum came to be.
The chinese .45ACP c-96 is exceptional, but a bit cruder in comparison.
They made them for ammo logistics reasons and while to be compatible for their thompson knock offs at the time.
I could understand for the collector and wanting to preserve their upper assembly. I want to as well. The thing is though, the whole idea is to run off a whole new upper, internals for the upper and barrels. Run these new ones off the antique lowers.