Is there any way to be able to tell, with the VIN, trim tag and original engine number, what other options it came with?
As far as figuring out options for a '68 Camaro from the above list...
1) The VIN will tell you if the engine was a L6 or V8 and if the body was a coupe or convertible.
2) The cowl tag will tell you if the body was a coupe or convertible, if the car originally came with standard or custom interior, and if it had a vinyl top.
3) The original engine assembly code will tell you which engine option the car had. The engine suffix code can sometimes also tell you what options the car had or didn't have. For example; if your engine assembly code was V0202MO, the engine suffix code (MO) would tell you the car
had a Muncie 4-speed transmission and power front disc brakes. The MO engine suffix code would also tell you the car
didn't have air conditioning and
wasn't a convertible.
This is very general and there are other variables (i.e. build date) that can help. Hope this sheds some light.
Paul