The Microair thermostat was smaller than the existing one. The solution Microair provides is some plastic buttons that cover the old thermostat holes. I thought that was unattractive, so I designed this mounting plate that fit the existing holes.
In the mounting places, I used 2 threaded inserts for 3mm machine screws. Then I put machine screws (10mm length) through the bushings into the threaded inserts.
The Micro Air that this fits is Micro-Air Easy-Touch RV 350. My existing thermostat was a Dometic CCC2, I could not find the model number of it but it might be a 3314080.015. The drawing I made of the base plate is in the photos.
After I did this design and iteration, I found out that MicroAir makes a mounting plate (KIT-35T-X01), so you might look at that if you just want a solution.
The author marked this model as their own original creation.