80MM spacer for UK Wall sockets

So i Bought a smart thermostat for my home and the casing did not fitting the wall monuted socket of where it was meant to go.

so since i am new to CAD, and my local DIY shop not selling spacers for wall sockets. i thought i may as well  have a go making one. the cost of a spacer online is £1.20($1.52) or so depending where you look. This cost's approx 12p(15cent) to print more then over half the price!

5 versions later and here we are. 

The spacer should just slip over whatever you have wired in (if already attached to the socket), if not then place between what you are screwing in and the wall socket, it should stand on its own in the socket will you are ready to screw in (it did on mine, miles may vary though)