More news in two weeks when I'll receive the pcb's.
Up to now, I did tests on protoboard with a salvaged Leg GT radio. Everything works great! I'm really hoping good result with the pcb's.
Here's a not so good simulated 3D image of the board. Please note that the connectors are not exactly as the real ones, but I gives you an idea of the size of the thing. For your information it's dimensions are 3.5'' x 1,12'' so it fit inside the radio.