Leica M Sync port cover
thingiverse
If your Leica M is missing this piece and you are not such a purist it can be a quick fix.
Download Model from thingiverse
With this file you will be able to print Leica M Sync port cover with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Leica M Sync port cover.