Try from the simplest solution, and so type Nirvana T-Shirt vintage or Kurt Cobain. Find a shop yourself, there are plenty of them, by the way, they are still made by a company that has a certain current legacy after Nirvana, here look at shops especially Rock.

From what the label indicates, we are talking about Giorgio Fiorlini garments which are unlikely to enjoy much value. I have seen such shirts on individual portals in the range of $15-20, as far as age is concerned I am not in a position to answer such a question for you either.

You can see that the site is run by someone with a strong grasp of Vintage, it is also interesting and engaging. You have a lot of unique items, especially the film series I like best, and they throw the styling I appreciate most in the eye, good luck with your business.