I've just received the lens that will be used for my next sliding box camera (an 8x5 rapid symmetrical). Unfortunately it came without the mounting flange as you can see from the image. So, I'm having to cut a square of brass sheet out, that I can then epoxy the lens too. This means that I can still use the lens on future camera builds too. How else do others manage with this? I was thinking about turning the thread down on a lathe and then mounting it to another flange, or soldering it to another flange. However, my engineering buddy was worried that it could damage the lens... so we binned those ideas!