Skywatcher Heritage 130P Secondary piece (remix)

This remix corrects a small bug where a curve in the finder mount obstructs the lip of the telescope (lordzurp is aware and is updating). BUT the real reason for it is to add a larger mount for a Crayford 1.25" focuser - 71mm base plate with 57mm M4 mounting holes. I have designed a 3D printed focuser and will upload here shortly, but I think this will also allow use of a commercial Crayford from GSO and possibly others.

If there's another suggested size for a “standard” mounting plate let me know - I would rather adapt my own focuser design and keep it compatible.