2020 Extrusion Camera Mounts

I started with kevinlo's camera mount, then added but2ene's backing plate mount instead of the ball mount (which kept breaking on me,) plus dizzee78's vented camera back. Then, I needed to mount it to the 2020 extrusion frame, but I could find no good options for doing that. So here's a simple set of mounts, one with single holes and the other with slots in case you need to tilt it for best use (depending on whether you are using the ball mount or not.)

The mounting holes are designed for M4+t-nuts, while the arms mount with M3 bolts just like the other models.

references:
original mount: https://www.thingiverse.com/thing:434600 (kevinlo)
backing plate: https://www.thingiverse.com/thing:2565178 (but2ene)
vented camera back: https://www.thingiverse.com/thing:949654 (dizzee78)