Assuming I didn't screw up anywhere, it's done.
Final dimensions are <tape width + 7mm>, so for 8mm tape it takes up 15mm and for 16mm tape it takes up 23mm.
I can go another 2mm narrower, but it will start to sacrifice some strength for my ratchets so I'm starting here.
This is going to take a while to print..
EDIT: Oh... I suppose I should provide some way to actually mount this thing. Not quite done it seems..