Your bird looks great! It's in much better condition than I had assumed. However, its' really hard to put a value on it. It's a desirable color combo as it sits, and looks like a great driver. Matching numbers 67 400 4 speeds are rare and desirable so my guess is you'll have a lot of interest in it when you decide to list it.
1968 Pontiac Firebird 400 Convertible - April Gold/Deluxe Black Automatic 1968 Pontiac Firebird 400 Coupe - Aegena Blue/Standard Teal 4 speed 1968 Pontiac Firebird 400 H.O. Convertible - Alpine Blue/Deluxe Teal Automatic 1968 Pontiac Firebird 400 Coupe - Autumn Bronze/Deluxe White 4 speed