The figures and distillation date for the Ardbeg 1977 release are picked from the german Whisky Archive website:
The 1977 release was never as hyped as the 1975 release, which was lifted to the skies by practically every whisky related person in the world. The demand for the 1975 was, and still is, outrageously great. But I can certainly agree that the figures are low for an Ardbeg release.
More suprprisingly was the release of the Ardbeg Committee Bottling. This 21-year old release was offered in a limited edition of 2500 bottles to over 6000 Committee Members. It was not sold out (as one could have expected) and you could still buy it from the Ardbeg Distillery's website until a year ago.
And C_I, I think the reason Port Ellen Rare Malts Editions are harder to find is the fact that (by the time of their release) most Port Ellen's were actually drunk. It's only over the last couple of years the demand for Port Ellen's has exploded and today everyone seems to be on the hunt for P.E.'s to put into their collections as this is regarded one of the rarest Islay Malts.