Well, from the vegetation in the background of the photos "taking it back to Ben" for repainting might not be an affordable option. I would make sure the rust is just surface rust and not deep. On the other hand that rust and apparent grease fire in the main chamber are good negotiation points for possibly offering less if you want to try. Assuming the rust is not an issue, either have it sandblasted or sanded with flap wheels, by hand etc.... and repaint with black high temp paint and it should look like new.
Considering a new Lang 84" deluxe is $5,500, as long as that one is structurally sound it should be a decent buy. I did a quick google search and the lowest price on a used 84" deluxe I saw was $3,200 (but they were not in need of restoration like this one is). So you might try for a lower price?