This mounting bracket is designed to be a form fit for both the aluminum siding as well as the black metal back plate of the G4 doorbell. It is a right-hand mount, but is designed to be mirrorable in PrusaSlicer to get a left-hand mount.
I have provided the FreeCAD file to allow you to customize so that it fits your own siding best. Most useful parameters are in the spreadsheet and will change the file appropriately.
The angle must be nonzero but relatively small. If you want the surface to be flat, set the angle to something tiny like 0.1 degree.
As noted above, this part was designed to be mounted on the right side, but I added an additional notch at the bottom to facilitate flipping the part in PrusaSlicer to get a left-side mount while still allowing the notches to line up.
For a left-hand mount, place the part on the build surface in PrusaSlicer, right-click the part, and select Mirror→Along Y axis.
If you wish, edit the FreeCAD document and remove the unnecessary slot from the sketch called “End Notches”
I designed this to take 10-32 square nuts in slots and use 10-32 button-head screws to mount the backplate. Tweak the values in the spreadsheet to set the fasteners to whatever size you prefer.
You may find that the wall mounting holes and doorbell mounting holes look misaligned; this is not a mistake: look at the flat-on view and the wall mount holes are centered; look straight at the angled surface and you will see that the doorbell mount holes are now centered.
Be sure to print this in a UV and heat resistant filament. I used Prusament ASA, but I suspect that PETG would work fine.
The author marked this model as their own original creation.