Space Bug possibility

Today I met up with a neighbour who had me service his VW Amarok for him.  The back of the vehicle was full of electric RC planes as he'd just been out for his regular Thursday morning fly.  As we engaged in conversation he mentioned he had a couple of Cox engines, a Babe Bee and a Space Bug.  Not sure if he's offering them to me, scouting for an unrealistically high price or just trying to work through the emotions of possibly parting with something which is of no practical use to him but holds a lot of sentimental value.  He says he purchased the Space Bug new in the late 1950s or maybe 1960.  On closer inspection I see it has the later style cylinder with larger thread glow head, so not an early version.  He's adamant it's original apart from a new later style head.  Looks in good condition although rather grubby. It still has the box it arrived in.  Just a plain cardboard box with "L. M. Cox Manufacturing Co., Inc. Santa Ana" label plus the original customs label.  He mail ordered it from the USA & has his name and Canadian address on the label.

Now, is it worth pursuing?  What would be a reasonable offer, bearing in mind we may be able to barter a deal with his car repair bill?  I told him the Babe Bee was a dime a dozen & I had as many as I'd ever need, but would love the Space Bug, but my ebay rule is never go over $35 for any engine unless it's exceptional. Did I offend him?  Who knows but if I did I may have lost a customer as well as the Space Bug.

Rod.