I bought a case of Chateau Petrus 1979 in the early 1980s. It was expensive for the time in the $30 range but not astronomical in price as is nearly any recent vintage of Petrus. This is the second bottle I have opened, and I reported on the first bottle here a few years ago. I have found no reason to hurry to drink this or the 1971 for that matter.
There were no cork or other issues and the fill was in the low neck.. The cork proved very difficult to remove - it nearly seemed to be glued to the glass. The color is still quite dark and it takes an intense light to see a bit of age showing around the rim. The wine is fully mature. It might or might not improve a bit more. However it is likely to keep well for many years. There is intense dark fruit with mixed spice, both in the taste and bouquet. The tannins are resolved and tame, but are easy to detect. There is enough acid, and the balance is very good. I believe I like the 1971 a bit better because it seems a bit more complex and intense than the 1979, but not much more. At 30 years old, Petrus 1979 likely is one of the top, if not the top, red Bordeauxs still drinking well and likely to last well for several more years