You are at least partially wrong. The Compac and the Presentation are two completely different grips. The Compac is a small grip for concealed carry, the Presentation is a larger grip for target / service use.
I suspect what you're thinking of is the Compaq Professional grip, which is an open backstrap, extra small version of the Compaq.
For an S&W J-Frame, I have the older 2-piece "Presentation/Compac" also. I don't see these on Pachmayr's current website. I also believe the current Pachmayr grips will have the medallions, but will otherwise feel the same.