I have seen a couple 66/67 Coronets with 66/67 Charger front ends with the hideaways...think it looked friggin sharp!
Not a 68 ( I like to see a 68) but Chrysler de Mexico, put the front of a 67 charger in the coronet, only in México
There was a green 70 Coronet with a Charger front clip floating around in the early 90's. They did a real good job and it looked like it could have come that way.
Back in the day, I went to look at at what was advertised as a '69 Road Runner, 383 4spd. car at a local used car lot ("Quick Carl Cole's Auto Sales"). Red with a white interior, looked pretty decent. Noticed during the walk around that the front sheet metal was Belvedere / Road Runner, so was the dashboard / interior, but the rear was a Dodge. Never did get to see what it said on the title / ownership. Kept walking out the door.