I'm in Wisconsin. I'll respond to your PM shortly.
I have (4) 5th Gen Celica's now, all 100% stock original, all with System 10 setups that are original, 2 of them restored.
They are:
- 1993 GT Convertible (restored) - 79k miles (white, repainted with white metal flake clear coat)
- 1992 GT-S: original time capsule - 72k miles (super red)
- 1990 All-Trac (restored) - 122,000 miles (super red)
- 1990 All-Trac (original time capsule) - 82k miles (medium red pearl)
The (2) All-Tracs are actually my son's, but he give's me the privilege to assist with restorations. I do mechanicals, electricals, interiors, etc. I let the body shops with their equipment handle body restoration and refinishing.
Regarding speakers (we've had 2 5th Gen ST models in the past also), I've never had a blown speaker in any of these. The door woofers had the foam dry-rotted in every one of the System 10 vehicles though. There is a place in Indiana or Ohio which re-suspends them for a very reasonable cost. With the OEM speaker housings with air porting and all, I've never heard another vehicle audio system with sound quality so clear & precise as the System 10 setup. I've only ever experienced one amp issue - where one of the door woofers would fire on it. While those amps aren't particularly powerful, they are full-wave rectified units from back in the day when full-wave could be had (today they are all bridge rectified) so the sound quality is tremendous. And in a small coupe, one doesn't need 500-800 watts. 1/4-volume is way past my tolerance of sound pressure. So you keeping your original amp was a very wise decision. But those head units were very trouble prone. I'm expecting yours to not be perfect - but I'm hoping I can restore it.