Rolleiflex SL66 Magazine Light Leaks

Hey all,

So I've been having issues with light leaks on my Rolleiflex SL66 magazines, and at first, I was unsure about where they were coming from. As a result, I've had the magazines disassembled multiple times to try and find the issue, to no avail. However, just recently I found the issue, the back plate of the magazine does not fully press against the body of the magazine. Essentially, there's a small enough gap between the back plate and the magazine itself to let light into the film chamber.

How should I fix this? I've tried adding some light-proof foam to the interior, but the material I have is too thick and probably shifted the plane of focus a bit. So far, the only solution that kind of works is having a strip of gaffer's tape around the bottom of the magazine. Anyone know how I could fix this? Its not down to the screws being loose, in fact I tightened one of the screws so strongly that the entire head cracked off, which was fun to deal with.

Thanks