MAD electrical upgrade question??

Thanks all for the advice. I just finished pulling my aching arse from the front floor of the car. I removed AC diffuser to see if its remotely feasible to do it from under dash. Not a damn chance! Lol. Sooo gonna pull bezel at least partway. Reasons to pull.
1 Ammeter bypass.
2. Factory tach needs calibrating. (Under warranty)
3. Some dash leds non op.
4. Dbl chk dual front speakers I installed in spring.
Damn this **** snowballs lol

Under dash harness in great shape. I believe they are M&H repops, as 2 outta 3 under hood harness are M&H and in great shape.

Only damage to wiring/bulkhead that Isee is a slight melt point on bulkhead when fusible link under hood burnt up.This happened 4 years ago when Dad bought the car and was due to a bad alternator (thanks to Dels diagnosis). Melting was minimal on bulkhead and no damage to any wiring inside cab.

Ben I have a Demon IVR I purchased from you. Is this something that can be installed relatively easily? I guess like you said it would need a complete R&R ??

Also I would like to add a Volt gauge. I have an aftermarket set of Coolant Temp and Oil psi mounted under dash. Lots of room to add the 3rd gauge.

Thanks all!