JD 301 won't go into park

[MDCII]

Hey guys as the title states. I'm buying a 301 tomorrow. Tractor is in great shape, loader works brakes work pto etc. was able to drive and operate it move dirt with it to see for sure. Anyhow the only issue known with the tractor is that it won't go into park. Owner says he has tried what he can and it just won't go. Anybody have an idea as to what a common issue is?
Thanks

 

[Tx Jim]

It's possible tab that shift handle sets in on shift rail has broken off. I've seen several welded back in place. End of shift rail can be viewed by remove cover with the 2 shift levers.