While I never mail ordered anything from any of the ‘rocker supply’ companies advertising in various magazines and comics, I did frequent a few stores that had the model down. Stocking all the cool jewelry that included everything from skull rings and iron cross necklaces, used leather jackets and DIY studs and spikes.
Growing up just outside of Seattle, the shops we went to were on The Ave in the U-District (University Way Northeast) which was just a quick bus ride across the 520 Floating Bridge from the Eastside suburbs. The music was loud and there was no shortage of t-shirts and back patches from all the coolest metal, hardcore, and punk bands. 
While definitely not a record store, they usually maintained a limited stock of a few titles from local bands like Coven, The Accused, and The Mentors – usually the more offensive, the better as they jived with the shop’s overall persona.
Looking back, I don’t recall the name of either of these shops, both of which were nearly identical to each other, though I’m not even sure I knew then as we just interchangeably called them ‘Rocker Supply’ and everyone knew what you meant 🤘
https://psyne.blog/product/seattles-best-rock-1971-vintage-mens-t-shirt/
