I had drawn up in CAD and 3D printed some prototypes and test fit to one of the MTX75 gearboxes I have in the shed.
This model is a 'gully gusseted' version and how I'd anticipate it to look once fully assembled.
https://www.youtube.com/watch?v=BmuzDiWLgL4
Press-bending limits what you can do because of the way any bend tool needs to access the piece. SO this is what was printed and test fitted:
Lukeyson