MPhillips wrote:
1975 Chateau Greysac - Cru Bourgeois - Appellation Medoc Controlee
1978 Chateauneuf-du-Pape - Clos de L'oratoire des Papes
1975 Chateau-Lascombes - Grand Cru Classe - Margauxl
The '75s you have are both from Bordeaux. That year in Bordeaux is legendary for the hard, long-lived wines it produced. Many '75 are only now becoming drinkable. I have no firsthand experience with either, but a Cellartracker user in '05 said that the Lascombes was still alilve and kicking. '78 was an outstanding year in Chateauneuf-du-Pape and the Clos de L'Oratoire might still be quite interesting.
None of these wines will doing very well, however, if the storage conditions haven't been good. From the way you describe the cupboard, I suspect that the wines probably weren't kept terribly cool. As a result, they are almost certainly well over the hill.
However, no wine, no matter how ill-treated, will hurt you. So, why not open them and find out for yourself how they are? Just be prepared to find something that isn't very pleasant to drink and maybe have a "backup" bottle handy. If you do choose to open one, pour out a small amount immediately after opening and give it a smell. Wait 5 minutes and smell it again. If it seems better (less stinky or fruitier) you could very gently pour half the bottle into a different container (carafe or empty bottle) and then fill your glasses from that. It'd be a good idea to do this (it's called decanting) anyway, as the wines have almost certainly deposited sediment inside the bottle, and that's not very pleasant to drink.
Mark Lipton