ETX-125 HELP!!!

Greetings...

I bought a custom built etx-125 that appears to be built like a tank.
Problem is, I have no way to get it mounted. I need a set of tube rings. I
measured and the 5.75" rings from scopestuff should work. Does anyone know
any other sources for a set of rings for a bare etx-125?

Also, can anyone verify that diameter? Help please!

Thank you,

Doink