So I am a newcomer to the vintage watch game (as well as this forum) and have just started my collection. I'm very excited! I have become very interested in 70s era watches and especially jump hour watches. I have never bought a watch online, and I have read warnings to stay away from auctions on ebay. However, just for fun I made some very low offers on ebay that some reputable sellers were actually interested in. I have shopped on Ebay a lot for other things and from my experience most of the reputable sellers on Ebay who have hundreds of sales are not out to scam you. But my question is, if a reputable seller guarantees that the watch is authentic but has no paperwork or original packaging, what are some good questions to ask to make sure the watch is authentic?
For example, I was thinking of trying to buying this watch (click here) for around $500 although I know in good condition it is worth much more. The seller is actually interested because they realize that they have no paperwork and the strap is in poor condition and may need to be replaced. Is there anything in regards to serial numbers, engravings, markings or anything specific I can ask to verify authenticity?
Basically, I'm looking for some good questions I can ask when purchasing vintage watches online, not only on Ebay but on other sites as well. Any help would be greatly appreciated!