Gravity Rewinder Adapter

First of all, big thanks to Vincent for designing and sharing all the great rewinders. I started to use the Auto-Rewind Spool Holder for my MMU. Now I'm testing the gravity based rewinder. However, I wanted to reuse the the auto-rewind spool holder and this is why I designed this adapter. Currently it is still flagged as work in progress because I wanted to test reliability for longer time. Feedback welcome.