All good and all except this most of the conversion to 7.62 ammo came after the war since PLA lacked enough weapons to arm everybody and even with the war over they still had a civil war going and this is one of those weapons modified after the war (They did the same to sten they converted it to 7.62 after the war)
but if you truly want a Chinese Converted SMG
There is chinese copy of M1921 Thompson looks funky(Taiyuan Arsenal Thompson in .45 ACP)
These were used during the Central plains war in which nationalist captured 1200 of them from warlords also communist captured some in mid 30s and gave them to their elite troops
One of the more cursed Thompsons I have seen is this one on the left, is a photo taken by Harrison Forman in China (1944). The stock seems to be modified with an M1 carbine stock.
After a quick research yeah thats indeed a Thompson but a wierd one
its chambered in 7.63 muaser
Its name is Sichuan Type submachine gun and was made during either 30s or early 40sat workshops in Chongqing, then part of the Sichuan province hence the name and yes some were used in second-sino-Japanese war and is in fact largely a copy of M1921
I would love to have this as a GO weapon for Japan, unless we get Chinese faction, though that might not happen, Chinese players themselves said that politics make that difficult.
And The Type Hua Quick Step Autorifle(This one has no photo only an image wich imagines what it would have looked like)(Apparently they found about the rifle in 1974 when they were checking old warehouse and did find the rifle laying around but no one took a photo)
Artistic Representation
Its 10 round short recoil rifle according to description given by the people who found it