If you are going to sell it, I'd leave it up to the buyer to decide whether they want good wheels to run it or originals.
I think I agree. Immediately after buying this, I HAD to run it - it's the operator thing...... When I did, I found that it had reverse and neutral only - one brief spurt of forward, and that was it - and it ran poorly in reverse. So I HAD to fix it. After a thorough motor and e-unit cleaning, I reassembled using the original brushes (good condition) and VERY lightly oiled the mechanisms. It now runs like a champ. I would normally replace the brushes on ANY repair, but again, trying to keep things original, no parts were replaced on the engine, only cleaned.
That said, there are other things that still need attention, like the trailing wheels obviously - it needs to be cleaned (all original dirt is still intact) and it needs bulbs replaced and definitely needs some new cloth covered wiring. I have not done any of that at this point, thinking the same way you do about the buyer wanting to do it his way, so.... that's where things stand. I guess the next step is to get it appraised by someone who's better at that than me. And if I don't like the appraisal, then guess what - I'll just keep it!! 
Thanks!
Things are in process at this point...
