Mr mow it all:
I am having problems with my email so I'll post here in case you don't recieve them. I have 2 electric pto clutches in stock and they are both from Scag mowers. The one for sale is from a wb 61" deck and I think they are basically all the same. We have interchanged with no problem.
The part is a Warner Electric # 5215-99
Pulley # is 2846
Shaft arbor hole is 1"
Used about 150 hours. Nothing wrong with it.
Check with your Scag dealer to see if it will work. The last time I bought a new one it was $160.00. $475 plus labor sounds real high.
You could have a switch problem. Just turn the key into the on position and short out the pto switch. You should here a strong click. No need to start the mower to do this.
If you get a "click" then replace the switch. If not, make sure that the wiring is good from the switch down to the clutch.