Canon FT QL Repair Manual

Help, I am trying to service broken a canon FT QL mirrorbox (Not FTb) and I cannot find a repair manual or any reference for how the mirrorbox should function. They are different from those in the FTbs which I have worked on before.

Does anyone have a reference image or a service manual for this camera?

Unfortunately I couldn't find that specific model's service manual available online. There was one for Canon FT being sold on eBay, but that may not be helpful.

I have the NatCam manual for FTb, downloaded when it was free, and available if you need it. I would have assumed that the mirror box would not be that different from the original FT, apart from the cam to sense the pre-set aperture. I'll find out when I finally get around to servicing my FT.