Hello:

I've come here just to see how's the bussiness arround auctions in the USA and I found this! ehehehe

I'm Portuguese. I live 15 miles from oporto and I probably can give you an aproximate value of your bottle if you tell me which is the cave that made the wine and the year of it.

If it really has 40 years should worth 350$ at least.

You know that here it will be much cheaper, because we are near, of course!!

also check:

wine-searcher.com/regions-oporto
or search for it:
wine-searcher.com/find/oporto+vintage/1/portugal