That FD 35-70 f2.8/3.5 lens is a cracker. Bought an nFD example over 40 years ago and it was an excellent performer. Canon should have put a red ring on the lens. Mine has developed a fault where I think the the pins that engage the zoom helical may have failed as when I tilt the lens it feels like one of the internal lens groups is shifting back and forth several millimetres. It's now in honourable retirement being replaced by the last 35-105 / f3.5 zoom. A bit heavier but a good performer. I still have a mint A1 amongst other FD bodies so I'm not really in the market for more FD bodies.
Good luck with the sale.