Phong 6538 case back size

[Kime]

Does anyone know if the Phong 6538 case takes a gen case back? or does anyone know of a display case back that will fit? I have seen plenty online for gen 1675s but none for 6538 and beyond that I don't know if Phongs case has gen thread specs.

[Revere]

I'm also curious about this. I don't think there is much of a market for a 6538 display caseback, and I'm trying to build one that is as original to the James Bond issue as possible. However, I would definitely be willing to get a display caseback!