Pony motor clutch assembly question

I have the pony motor off my 720 and have the clutch housing and transmission housing separated, and I just installed a new clutch disk and brake plate. The over running clutch and bearings all look good.

The book says to adjust the toggles so there is a 5/8" space between the REAR surface of the cover plate and the toggle surface when fully depressed. Since this seems kind of difficult to measure easily, I found that the cover plate is 5/16 thick, and added to 5/8", I get 15/16. I then put a straight edge across the front surface of the cover plate and measured between the edge of this and the depressed toggle and adjusted toggle till I got 15/16. Does this seem correct?

Another question, when I have to reattach the clutch housing with the motor , how do you line up the clutch disk with the drive shaft in the clutch housing? Since the clutch disk is loose, it slips off center, so how do you align it with the shaft in the housing?

Is it easier to assemble the transmission housing with the clutch housing first and then try to attach this large heavy assembly to the motor, or is better to attach the clutch housing separately and then attach the transmission housing?

Any help or tips would really help.

This is how I have made that measurement. Follow the manual (70 D service manual) says "with toggles depressed until pressure plate contacts clutch disk, measure clearance between clutch cover and three toggles (as shown in Figure 65-20-13). Measurement should be 5/8 inch. Note I am looking at the 70D service manual and the 720 manual may not be the same but I do not know that for sure.