I'm too far away from you to be a buyer but I will be glad to offer my opinion on value. In short, vintage wind generators are tough to put exact values on; thereís not a huge market from which to base value and factors like rarity, completeness and condition can have a huge effect on the end number. A relatively common model, like a 617, that is complete and in good, original condition can sell in the $300-$600 range. For that model with those qualifiers, I think thatís a fair price range for both seller and buyer. ďGoodĒ meaning the tail graphics are at least legible, the generator is not stuck and the prop is there but not necessarily spin worthy. ďOriginalĒ condition meaning it has never been restored and has the majority of its original parts. One should not expect to be able to operate an original condition, 80 year old wind generator without rebuilding the generator and replacing the propeller with a new one or a least one that has structural integrity. If the propeller has any cracks then itís a display piece. A 6V propeller can exceed 500 rpm and can cause considerable damage if they come apart at speed.
I advise people to sell locally if possible. Shipping is a pain and expensive. Even if you disassemble and package a complete 6V Wincharger with tower yourself, it can still cost $150 to $200 to ship via Fed-Ex ground within the lower 48.
I know these are some pretty generic guidelines but it should get you in the ballpark on putting a value on it. In the end, what I think itís worth is irrelevant, itís worth whatever someone is willing to pay. I think you should keep it in the family but if the decisions been made then I wish you good luck in selling.
p.s. to anyone reading this forum post from the future, keep in mind the value range given here is based on 2017 prices. Iím certain, vintage wind generator values will have tripled 10 years after this posting was written.