…the ‘68 and ‘69 bodies have completely different tail panels.

The side scoops would normally be the same for ‘68 and ‘69, but the ‘68 body has the basic scoop detail, while the ‘69 forward quarters have the factory optional add on / bolt on scoops.

Side markers are round and small for ‘68, rectangular, larger and lower for the ‘69.

Lastly, the fender tips and valence (just below the grille) differ slightly since the grilles are different shapes between years.

I think in this case it would certainly be easier to just repair the window frame.

Are you wanting to build a stock ‘69 Convertible, or the Mission Impossible custom?

Turns out that the car on the show was a ‘68, and had different custom pieces than the ‘69 kit, which never existed in that configuration on the show, or as far as I can tell, in real life.

I might try to build the ‘68 MI car from the show. There are good pics of it on IMCDB.org.