582: Rotary disk timing

582UL. Recently had an overhaul.

The manual shows the rotary disc in a certain position, figure 8.17, when the piston on the gearbox side (PTO) is in the top position, TDC.

(Maintenance manual Heavy, 79-00-00, page 14)

Also, in this position, the locking pin will lock.

Is this correct?

I see in old manuals and other types of engines that it is sometimes the piston on the generator side that has to be TDC.

Now I'm confused.