Hi Coastie, I've looked at the Fender schematic for the M-75 and if you have a twin humbucker layout then I too think it would be identical. If you go to the Guild website and look at the schematics for Bluesbird,Bluesbird 90, StarfireII etc the wiring is identical. The only variation may be the value of the caps for the tone control but they are in the same place in the wiring.The thing with the M-75 schematic is it shows the same type of wire used as in your M-72. I know that schematics can look like just so many lines in black and white and the Guild schematics show a much simpler layout of the same thing.You will do it!!
All the best me old china,Steve.