Vintage Kramer Seinfeld Coffee Mug I'm Doing What I Do Always Done It Way 1993

This is a 10-ounce coffee mug featuring Kramer (from the TV show Seinfeld) on one side with a quote stating, "I'm doing what I do. They way I've always done it and the way I'll always do it." The opposite side has the Seinfeld logo. There is no mention if it is microwave and dishwasher safe, so assume it is not to make sure the item isn't damaged. The handle of the mug has a small light brown stain, which has not come off with regularly cleaning attempts (see pictures). There are a couple of tiny specks that also have not come off-- one is above the "l" in Seinfeld and the other is on the interior of the mug. I do not know if they can be cleaned using other methods. Structurally, the mug is in nice shape with minor wear - there are no chips, cracks, or other damages. May need minor touch-up cleaning. See pictures for more details. If you have any questions, please let me know. Thanks for looking!