update….photos of speakers and info sent to Boogie people stateside, and to Glasgow, and they replied that they are the original EV spks…apparently re-echoing kit is available, but sounds a tad expensive to me …..
I also have an Ampeg 4x10 and replaced all 4 spks when I first got it to a 'truly' amazing effect….(drummer loves it guitarist hates it ..ha ha typical) however, I am thinking re-coning rather than replacing at the moment = thanks all for your comments….