Again, thanks for the nice comments.
The process I came up with is not difficult but not "magic" either. I started out by sanding the entire area for a smooth surface. Then, I melted some original rose pearl (it helps to have that!) and carefully applied it with a brush to any areas that were too low and would show with the flange in place. A standard head dropped on the drum without a tone flange would have completely hid any of the damage but I really wanted that flange in place and to be as original as possible.
After 24 hours, the "goop" had hardened. I wet sanded it a bit and then polished with a plastic car polish. It still didnt look that good so I did a second and third application. It's not 100% perfect but I am really pleased with the results. A few times I almost "threw in the towel" but I kept at it. I was tempted to smooth it out completely but the more I messed with it, the greater chance for a disaster. Acetone is tricky stuff. While it melts the goop to a liquid texture, it can also damage the good original wrap. After three applications I decided to stop.
This acetone process works wonders but it also comes up short. If you use any wrap pieces that have a colored backing (like wmp, bdp), it will overpower the pearl color. However, the pearl part could be extracted from the backing but I have yet to try that. In theory it should work.
My first attempt at dissolving pearl was on a red ripple Rogers set that had cracks. That worked pretty well but not great. I tried again on a Radio King but the white backing definitely overpowered the pearl "look". Same with a bdp Ludwig set from the 30's. Came out looking like black plastic. A good solid repair but cosmetically, not so great. This Rose Pearl example is the closest to a total success I've had.
Here are some "before" photos and some "during" photos. It looks just awful before it was finally smoothed out. Unfortunately, my camera batteries died in the middle, so I didnt get all I wanted. I was hoping to get some of the second and third applications but I didnt. The drum in the photo with all the scraps is the "donor" drum, which was trashed. The good thing is the finish on the restored snare drum has the old cloth backing, like Gretsch used to use. However, the donor drum was a bit later and had no cloth backing. The cloth would have caused problems, I'm sure. Another BIG thanks goes to collector Dave Brown in the U.K. for providing the donor.