1971 IH 154 lowboy: Buy or not?

The owner wants $1000. It has a mid position mower deck in pretty good shape though it seems to slip when it cuts. The main drive belt is really worn: cracked and stretched to the limit of it's adjustment. I hope its not the pto clutch that's slipping. How do I tell? The three point cylinder needs to be cleaned up before cycling it down to see if it works. (I own a smalll wood lot and could really use the three point for yarding small logs out of the woods.) It seems to be in good shape: starts right up idles smooth does'nt smoke and sound really good.
I primarily would use this tractor to mow and to pull a small trailer around my place. It would also be nice to have a small scraper blade on the back for light grading of my trails. The tractor has turf tires in really good shape.

Any thoughts would be appreciated...

Tracy

Maybe I could ask a couple more questions:

The flow diverter valve that moves the hydraulic power from the mid deck cylinder to the three point cylinder is frozen in the down position. I have'nt bought the tractor yet but if I do can I take the cover off the housing where that plunger type valve is and try to lube it up to free it? (The three point cylinder also needs some cleanup before I try to run it in.) Where does a guy go to learn what it takes to work on something like this? Can anybody reccomend a good book on the subject? This tractor is supposed to come with the original manuals but I wonder how much help they will be...

Thanks again for your time answering my questions. I have 7 acres in the foot hills of the Oregon coast range and if there was ever anybody who needed a little "power assist" it's me. This is probably more tractor than I could ever hope to afford right now.

Warm regards,

Tracy