OK, I got the VR715, popped the cover off and drilled out 5 rivets to remove the circuit board. As expected, 4 of the holes line up perfectly with the original base - the ones for the 4 connectors. The 5th hole is a ground for the circuit board. I marked and drilled this hole in the original base, and everything fits perfectly. Very simple & easy. For final assembly, I will either use rivets or small brass screws. Sorry I didn't take any pictures, but I was moving too fast.
Now, does anyone know the correct plating for the base? I was going to have it silver cadmuim plated along with some other parts.