The PDG7 is nothing special, the value is in the groupset. Swap the parts and sell the purple frame.

Don't be concerned about using second tier Shimano for a 91 Paramount. The performance is every bit as good as DA from the same era. I have it on my Merckx Century, works flawlessly. Plus, you can swap in other Shimano components for special event builds, e.g. a Deore RD, 6206 pr Deore 110/74 crankset, and 11-34 cassette for mountain type climbing. Can't do that with DA, not compatible.