I'm very happy to have been included in James Reaney's yearly Holiday Gift Guide (under "O" for "Original"):
Original, hand-screened T-shirts with logos including a Nihilist Spasm Band-inspired kazoo image are available from London artist Diana Tamblyn. She also has comics, $2-$24.
If you're in the London area, I'd be happy to do arrange a drop-off or pick up. I have plenty of tees in just about every size and various colours. Email me for your preference and to make arrangements.