At first I told the seller "no"...but I then called some dealers and got feedback that it probably wouldn't be THAT major of a repair...so I pulled the trigger. Seller did agree to take $300 off the asking price.
Once I got it home I was able to take a better look. It may sound silly but it was hard to accurately see the fluid level on the trans fluid dipstick. It actually was several gallons low. I filled it and it seemed to take care of the issue. Then I used it for about 4 hours straight working my driveway and doing a little mowing. Once it warmed up, though, the lift got slow and started jerking a little bit again.
I'll change the filter and clean the sump screen at some point. It still works, just not 100%. Good enough for now.
I think I made the right choice. My neighbor came over and was surprised when I told him it was a 1967 model...said he would have never guessed it was that old by looking at it. Admittedly it does have some "character" LOL...but nothing that a can of JD green paint wouldn't fix. And, given the overall condition, the price was really good based on comparables that I had seen. Like I said, I used it for several hours and everything else worked great - loved the power steering and good brakes after dealing with my old MF50 for the last several years!
Thanks to all for the input/opinions.