Beeze I printed out your pics and took them to work. The fitter I work with came up with an idea.
We used a piece of 2 in copper pipe brazed a cap and 1" adapter on the other end. I used a water heater element with the same thermostat you are using. we brazed in two female adapters that would take the compression fittings.
I just have to wire it up to test.
will try and post pictures later