I think your attempt of a restyle is well thought out and the execution is great! Of course, it does have a European style now, but there's nothing on a Corvette that hasn't strayed into their market to remain competitive. Best of luck, can't wait to see this one when it's finished!
Just for the sake of accuracy, Chevrolet 1967 and 1968 model years were similar, 1969-1970 were similar, and 1971 and 72 were similar. I won't go into the numerous details identifying any particular year unless there is interest. As I understand, there are 2 locations for a model 69/70 year grill. There was a diecast 69 model, or the promo models from 69/70. The diecast is much easier than the promo to find, and probably cheaper than just finding the promo grill. Best of luck!!!!