Do you know if the hyd fluid has every been changed and if so what type oil was put back in when/if it was changed?
With 547 hrs it's getting close to time for the second hyd fluid and filter change. It may have never been changed the first time or it could have been changed at 50 hrs and the fluid was replaced with something cheap instead of the proper fluid.
It would have come from the factory with SUDT and now knowing it has hyd shuttle shift the correct fluid would be extremely important. Even if UDT was used it would cause problems when the tractor was worked hard. Pulling a conditioner may not be a super hard job but it creates lots of heat. Heat is a tranny killer and in your case could also be a clutch killer.
I realize the 4 hrs you used it didn't just suddenly cook the clutch but who knows what the former owner has used it for.
Looking a different direction, might be worth having the hyd pressure tested. It may not have enough pressure on the clutch pack and it's letting them slip. I have a neighbor with a 9000 that had that problem with his PTO. It would work but lacked power. he finally complained enough that the dealer put it on a dyno. It only had 35 pto hp. The pressure was way to low going to the pto and it slipped. I'm just throwing ideas out there, it's hard to say what might be wrong.