Some of this illustrates the two basic problems with buying vintage vacs on eBay.
(1) You cannot see the object in person. Like anything else "vintage", the whole deal is very condition sensitive. It's not at all like buying something new.
(2) Also because you aren't buying in person, shipping is involved and when it comes to vacs, it usually involves more than a trivial amount of money. When you buy something small that doesn't work out and requires return to the seller, it's no big deal. Not so with vacs. High shipping prices also contribute to sometimes intractable problems dealing with a return to a seller. E.g., they don't want to have to eat even the original shipping which eBay/PayPal resolution usually results in.
Be very, very wary when buying vintage equipment on eBay.