By the way, I can't just ask him about the value of the port - he got it from his dad, who has probably had it for years and years.

Try froogle.google.com

I saw some prices listed for various types of port there.

The gin is probably OK to drink, but unlikely to taste as good as it once might have. The herbals that flavor gin don't age all that well, particularly in the presence of oxygen, so if the bottle is drawn down significantly, put a lot of tonic in drinks you make with it. Under tonic, who can tell good gin from bad?

Unless you give us label specifics on the port, we can't help you directly. Issue 22 of the Quality Price Ratio (QPR) wine lovers report gave some market valuations for vintage and non-vintage port. Just because a bottle of port is old, doesn't mean it is good, or valuable. It may be old just because the person who had it a long time didn't like port.

Thanks, paulsc - here are some label specifics that I should have put in my original post: It is Porto Barbosa 1980 Vintage Port. There's a bunch of other info on the label, but I don't know if it's important.

Tells me nothing about the vinter, country of origin, or distributor and I don't recognize it (but I'm not much into port, other than occasionally keeping a bottle around for guests I know might like it). A high-res picture of the label might help, or you could look for advice from oenophiles in your area.

It's Portugese, probably from along the Duoro river. I have a bottle of Barbosa a few years younger than that one (remnant from a former housemate's case). If it's been kept properly it's probably quite good although I have no idea if 80 was a good year; 85 certainly was, since the season was rather dry it resulted in a sweeter grape.

Wouldn't the alcohol in the gin evaporate over time if left open? My guess is that there is nothing "wrong" with the gin, but that it will be rather tasteless and have little punch.

According to this chart, 1980 was a ‘very good’ year (on a scale which goes average > good > very good > outstanding > classic). I’ve found 1980 vintage ports (although not this brand) advertised for anything between $35 and $90, so unless there’s something extra-special about your bottle, you’d probably not get a whole lot of money for it.