John, sorry to hear that you have that situation. Just one more thing to make an already complex build even more complicated.
Unfortunately if the entire fire wall and dash are replaced on first gen F-bodies all of the VIN plates and markings get are gone. There are partial VIN's on two places, one on the sheet metal on the vertical surface of the firewall under the passenger side fender, where the heater box resides, the second is under the removable cowl panel on the sheet metal near where the passenger side windshield arm mounts.
Did that sheet metal get replaced? If not you have a partial VIN, which should be enough to establish the VIN with the other ownership documents. Check this out for the location.
http://www.camaros.org/numbers.shtml
When I bought my car, I had a rather complicated ownership transfer. Working it out took almost 6 months. It could take less time though, you just need to start working it now.
If the below doesn't work out maybe you can do some sort of lien sale and use that process get a replacement VIN applied to the car. It will take the participation of the shop doing the work on your car. When they did a lien sale of my car it cost about $75, and it took care of the lost pink slip and any issues related to ownership.
Contact these guys and see if they can help. Cost about the same as a lien sale.
http://www.asapliensales.com/VV-Vehi...fications.html
They are doing this for you instead of going to DMV or the CHP who do this for the state of CA.
http://www.dmv.ca.gov/vehindustry/ol...ooks/ol301.pdf
http://www.dmv.ca.gov/forms/reg/reg31.pdf