At the risk of sounding shallow
and pedantic, he says the $50 Kay was his first guitar, and that the majority of his college practice sessions (pre-Rage) were the Explorer. The Canadian Pawn Shop guitar and solid state amp he mentions were used on "Tire Me", a single track from Evil Empire. (He even mentions the Drop D Tele in this video)
Again, I apologize for sounding like a jerk, I was obsessed with Tom back in the 90's/early 00's, so I read everything I could find. In my youth, I of course attributed his sound to his gear, when it really should be attributed to his mind and creativity.

If you have other info stating he recorded the debut album with an Orange, I'll be happy to add that to my knowledge. I was under the impression that by the time they cut RATM his setup was pretty fixed after playing live with Rage the previous year.