Gpo 232 with a 746 circuit board

[Andruffwoody]

Here is a problem
I have a gpo 232 with the original 3 wire handset which sometime is past history has been converted with a 746 circuit board. It seems not to work at all at the mo, is there a modified circuit diagram for a 746 with a 3 wire handset or should i just modify the handset. And then would it be ok to them just wire in a rotatone. Any help would be great.
Thanks
A