Found that the print was hitting one of the other screws on the mounting plate. Cut out a piece from the original STL so it would fit without filing down the side.

Mounts with two M3-.05 x 8mm. The 8mm sticks out a bit from the plate but does not rub on the cantilever. I would suspect that 6mm would be fine but the 8 was the shortest I had to work with.

The original model was created by Betram69.
https://www.thingiverse.com/thing:4563093