I picked up a 540 front PTO that fits a 420 or 430 a while back. It is New Old Stock but was seized up. There will be an upcoming video series on opening the PTO up and figuring out if we can restore it. A few pictures of the initial breakdown.
My initial impression is that this PTO sat through a lot of heat / cool cycles with lots of condensation.
First gear I cleaned up looks usable but not new by any means! Lots of rust pitting.
This shaft worries me a bit given the rust pitting is on the driveshaft where in the needle bearings go.
Videos on this project will be coming out over the next few weeks.