The wine is Romanee-Conti 1970, no. 006303. I bought a few bottles of this in the early 1970s as well as some of the 1970 La Tache. It has been stored properly be me since. Most red Burgundy from 1970 was a bit lighter than the best years, and much is now too old.
I have tasted this 1970 Romanee-Conti about every 10 years since it was 10 years old. It and the 1970 La Tache were not very good early on (except when very young before they went into an extremely long dumb phase). At about 20 years, both Romanee-Conti and La Tache started to develop interest. La Tache was more full in body, but Romanee-Conti developed much more complexity, especially in the bouquet as the wine aged more at about 40 years. At present, the Romanee-Conti is still holding well and has a bouquet of complexity that I have not found in any other dry red wine.
If you read reviews of older Romanee-Conti and La Tache, you will find many that are not so good. Of course cork failure sometimes lets oxygen in that ruins the wine. It is asking much to expect a cork to last and seal properly over 40 years, and storage should be nearly perfect. Because of often non-ideal storage and possible fraud, I would not buy any bottle of Romanee-Conti now unless I had a notarized statement giving the history of all previous owners and how they stored the wine.
Empty Romanee-Conti bottles with good labels are often bought and some likely are filled again with who-knows-what. Making a new branded cork should not be a great problem. Also it is possible to drill a small hole in the base of the bottle and draw out the wine through it. Then the bottle can have other wine injected through the hole, and the tiny hole can be sealed with plastic so that it is very difficult to notice unless someone examines the bottom of the bottle very carefully. The
1970 Romanee-Conti cost about US$ 50 in the early 1970s, if you could find it. Today, even fairly recent better bottles can sell for several 1000 to over 10000 $US. In his 2013 Pocket Wine Book, Hugh Johnson suggests cellaring Romanee-Conti for decades for best results. Although the 1970 is not the most famous Romanee-Conti around, I have to agree with Johnson's suggestion.