BBC Micro keyboard hole plug.

thingiverse

When restoring vintage BBC Microcomputers, the perforated area on the keyboard that originally held the speech expansion ROM cartridge is often damaged and repaired with messy tape. This crucial component plugs neatly into the hole, significantly improving the machine's overall appearance. The fit is extremely snug, which is why I chose not to use hot glue on the rear - it wasn't necessary in practice. However, if you're concerned about small prying fingers getting into the plug area, a small amount of glue might be beneficial. A cut-out section is included in the plug design, and this must be carefully aligned with the speaker to prevent any intrusion into the space where the plug goes. I designed this component using FreeCad, which I used intentionally to ensure precision and accuracy. As such, I've included the relevant files for anyone who wants to improve or modify the design.