Sorry forgot to mention up above, until PoH release the only caster armor was Cryosilk. The robe stopped dropping with PoH release I assume.
https://wiki.project1999.com/Cryosilk_Armor
Also, as a historical note, Rogues were meant to have class armor drop off Scarelings but it was forgotten / not implemented.
Edit: Wow there are some really cool timeline points of interest from that Guide forums post! Fletching kit wasn't 8 slot till Sept.14 1999, storebought arrow range was 50, Silk armor wasn't tailorable, many other tidbits.