Rust is a little worse than the '76 auto westy deluxe that I sold last year.
The engine can be fixed and it isn't a FI so no worries on the computer / hoses, etc.
Heck I'd say get it and find a couple of heads (EXPENSIVE) and roll it.
I have 2 busses now and am looking at a 3rd (1 is for parts.)
You could get the Creative car craft filler set for installing a beetle engine in a bus, parts are cheaper.
Good luck, VW's are WAY popular here now and busses are going up in $'s.
Get it rolling / driving - then do a cost bennifit annalasys and see if the profit ratio is worth putting the extra $'s into the rust repair and the pop top.
KC