Having spoken to Simon a bit I’m really liking the look of Altec 828 cabinets(VOTT A7\A5), then some Le Cleach ellipticals and then something above that.
My first issue seems to be driver choice for the 828’s. Altec 515 and 416s aren’t cheap and most I see look of dubious condition. The remade ones by Great Plains are spendy too at $1400 and $1200 each.
I have seen people use JBL 2226 but can’t find much more info on other drivers to use.
Picture for attention
Have you modelled anything in HornResp? I’d get that going and have a play. With a cabinet that combines back leading and front loading, a “fairly similar” driver may well not cut the mustard.
Covid does strange things to people, It is probably a side effect,
You will have given up on horn loaded speaker design next week once you are feeling better.