This is a late 90s CNNP 7581 ripe brick. I had acquired a carton of this tea during one my early visits to Guangzhou. I was introduced to a Chinese tea drinking group and I had later got to purchased this tea from a retired CNNP tea manager in that group. It was from him, Mr Chen that I started learning about pu erh tea and storing pu erh tea as a hobby.
This tea survived my trip to Europe. Unlike my raw pu erh tea, this 7581 did not "hibernate' during the journey here. The taste and aroma was good exhibiting old earthly notes of old books and leather. This tea is a workhorse brewing up more than a dozen good infusions in a tea session.
This only thing I found challenging was brewing tea in this cold wintry weather. The tea cools very fast. I like to drink my tea reasonably hot, but over here in Paris, the tea cools down and was luke warm after 10 min. I had to finish my tea quickly in between infusions. I wonder whether Chinese tea drinkers, in winter, drink their tea quickly in between infusions.