69 Barracuda dash help/opinions

How to remove this instrument panel is in factory service manuals. I dont know how much of that will apply to what you have there.
Everything behind the bezel to go back to OEM is available used in for sale section here at reasonable prices. The one gauge that is not so available is the OEM tachometer. Aftermarket does have new tachometers for this rally panel.
Taking that bezel back to OEM may not be doable. Odds are its butchered to the point that OEM lenses will not mount back in it. If this was mine, I wouldn't touch it until I had a complete OEM instrument panel, bezel and all, on the bench, bolt in ready. Of course you can't correct the wiring, speedometer cable?, etc.., until that panel is removed, so the R&R might not happen in one day.