Child art added to give an idea of what I'm thinking of.

Indeed that was the context the mid-horn size got raised - and I never did use the edging method. But it was mentioned that the flare would benefit from being slightly bigger so, when I get round to remaking it I was going to increase the throat to corner distance by 1 inch with the top and bottom faces slightly curved to the middle with a 2 inch increase. The 'drum' holding the driver would be made from flexible MDF (MDF sheet with slots cut 2/3's the way through the thickness at regular intervals) formed over disc of ply. Well that's the plan, but then again, there's the power-amp upgrade, the preamp upgrade......

Paul