So, here's what I've received.
I’ve attached the following Winchester trench gun photos of the heat shield rivets:
1. WWI Model 1897 adaptor (this gun is in about 98% condition. See how the rivets have been ground down flush with the heat shield so that when blued they do not show).
2. WWII Model 97 adaptor (notice how the rivets are visible).
3. WWII Model 12 adaptor (this gun is an unissued Model 12 in about 99% condition. The rivets are also visible).