That's how one of my readers in the US described and kindly sent it to me. It turned out to be a young, twice baked tie guan yin (probably from Fujian, China)! I can say so with absolute certainty, because it tasted almost exactly like my top grade Tie Guan Yin and I know what an old Dong Ding tastes like. I even decided to brew my TGY in parallel to make sure. A good tea, though, this sample. I liked the fragrant nose of the dry leaves. I love to drink heavily baked Tie Guan Yin, especially now in winter. It's such a good tea that it shouldn't be sold under a false name.
But this experience shows that one has to be very careful with claims of old oolongs: using a good baking technique, a tea middle man (farmers only do light baking, if any, in general) can give young leaves an old appearance and taste.
So, how can you spot the difference?
Young leaves need to be baked more heavily to bring them to this level. A good tea baker will even let the leaves rest for a few days before baking them. The result are leaves that are more 'charcoaled', hurt by the heavy fire. They don't open up very much anymore and feel very dry. The charcoal smell is also more pervasive.
Old oolong leaves, on the other hand, have usually been more lightly baked, once every year or so. Just enough to freshen them up and dry the accumulated humidity. They will open up almost completely and you can see their color change from black to brown and almost back to green as you brew them longer and longer. Their fragrance is also more complex: it starts with the sweet roasting flavors, but you'll find also smells of old wood and at the end some even show a hint of their original aroma from their youth.