Don't know if they work on PCU governors but it's worth a call. Redline Aviation in Colorado had outstanding service when I got my Hartzell governor overhauled last year. Lowest price and quickest turnaround.
Aircraft Propeller Works, Inc. offers complete sales, repair, and overhaul services for aircraft propellers and governors. We service all major manufacturers, including Hartzell, McCauley, Sensenich, Woodward, Aero Technologies PCU 5000—blades, turbines, hubs and governors.
I just wanted to let everyone know about Redline Aviation in Colorado. I sent my governor in to get it checked out. Dan, the owner, said it checked out perfectly and didn’t charge me to test it. It’s rare nowadays to find honest people in any service business. For an OH his price for a PCU5000 is $675 compared to $1000-$1400, which the $1000 one wanted to charge $125-150 to test it.