OBERHEIM SYNTH

First at all, Hello to the members of this list. 
My name is Sergio, from Spain. 
A friend of mine gaves me his Xpander for repairing, and now I am in 
a very big trouble with its PSU.
I don't know if it is an earlier or later production unit (it has no
serial number) but the power supply is different to that described
on the service manual. On the schematics they represents a PSU with
just 2 transformers and a 5561 as pulse width IC... and mine's have 3 
transformers and a MB3759 as PW IC. 
I don't know if someone here would have that PSU scheme, it seems to be
a very hard-to-obtain info... but, if some Xpander owner have that type
of power supply on his unit I would need just "detailed photos" of it, 
and possibly the values of the components, since there are some missing
ones.
Any kind of help will be very welcome and appreciated.
Thanks in advance.
Sergio