Hi Ray,
Yes and no.
The powerspark unit doesn't interfere with the vacuum unit and this should still work nicely. However, the unit doesn't move in and out, that only moves when you turn the adjuster. It's the coiled hook inside that pulls the base plate round. Two ways to test and take the cap of the dizzy and suck on the other end of the tub to watch it move, or hook some cotton round the same peg on the base plate, start the engine and see if the cotton gets pulled in a fraction when the engine revs. Could be a split diaphragm, or break in the vacuum pipe, which would also account for rough running (vacuum leak) and/or lean running at the top end. Equally, the adjustment mechanism could be duff allowing the whole unit to rattle around in the distributor body.
Replacement in both cases is the best course of action. They're available remanufactured at very reasonable prices from SimonBBC himself.
Michael