Where did you get your new bumper's? I got mine from "Auto Metal Direct". They are Authentic Mopar Restoration part's. Triple Chrome and nickle plated. Better than original.
If you got your bumper's from them, you still might be able to swap. I got a super deal on the bumper bracket's and, have been haggeling over the bumperette's. In the mean time, I've restored the bumper molding, and re-installed my original bumper. It's not quite, the end of the season and, I didn't want my car without it's hind end. I've had time enough to appreciate the mint bumper molding and, I have ALL the 73 part's. So, at the end of the season, I will take it apart, again. Have my 73' bumperette's rechromed. The rubber pad's are in excellent shape. I've seen many car's, with the slot's, patched in. They look great, too! Decision's...Decision's.
Good luck on what you decide! Oh, and I'm glad you got your car running good, too!
Pat