The rifle in the photo with the Johnson is a Pedersen self-loader. The ZH29 is in fact a ZH29 (they are rare, but do show up). The top LMG in the photo with the RPK is a Msdsen variant, and I think the middle one is a modified Japanese Type 11 (not too confident on that, though). The guns with the MG42 are both BAR variants. The 1919A6 is missing it's stock and booster, and the gun below it is a Johnson 1944. In one of the other LMG photos, the Bren is actually a ZB26, and the guns below it are a Chatellerault and an MG13.
Cool collection! They really have some neat stuff. There was a lot of interesting development and modification done by the Chinese, and it would be great to see a good collection of it.