No disrespect taken. I am just giving you my opinion. Not many 30-40 year old tractors are perfect. But are you worried about functionality/reliability?? or are you worried about everything being original?? Cause the 4600 isnt really a "collectable"....yet anyways.
Personally, I would rather have a tractor that looks like h3ll but is a good runner and reliable, than a tractor that has mechanical issues but is fine cosmetically, which is what it seems you are describing.
Again, this is just my opinion. Its hard to evaluate a tractor over the web. You asked for opinions, I have given you mine. You may end up with a tractor that looks parade ready but has a cracked block and be out $7500. Or it may be something simple and no major harm done. I dont know, I'm not there. But either way, I wouldnt pay 7500+ unless everything about the tractor was perfect. which it appears it isnt