Turf Tiger Drive shaft yoke bolt?

[flashbang]

Bought it used with a advantage deck. I removed the deck and drive shaft. On the PTO side it has a spline and two bolts that hold the yoke on to the PTO shaft. The gear box side has a spline that the drive shaft yoke slips on to and a bolt hole with no bolt in it. It does have a set screw. Since the manual shows a different setup I do not know if it should get a bolt also. I would put one in but this may cause a unbalance shaft and wrech the gearbox. Anyone know what the poop is?
The pics explain better.

[ed2hess]

I would put a bolt init and not worrry about it. Don't want it to come off. I am a little surprised about the heads on the bolts used they don't look like the kind I have on my gear cases.