Simon,
While I understand the paper issue (and in fact, think very highly of all your efforts), I think the Delta 25 would be a different story. I don't mean to imply that I know the effort involved in bringing it about, but I am referring to the universal appeal of it to traditional photographers and the fact that it would not displace any sales from your current line. There is nothing that advanced, that fine and that slow on the market right now. Rolls of TechPan usually yield a kidney, a liver and a first born at auction. Efke 25 will always be a different animal (and will remain loved I am sure), but I think a few dollars now going to Efke would also find its way into Iflord coffers. I don't think PanF will be affected any more than FP4+ is affected by Delta 100. The glowing, maniacal eyes and drool everywhere that invariably accompanies any mention of this film makes me think it would be a best seller for you for a long time. Most people I know who shoot film get excited at the very notion, and even some digital people seem very intrigued with the idea once the potential capabilities of this film are explained to them.
My highly un-scientific "market research" points to this film as being a really, really good idea for Ilford - and certainly for all of us who would buy it by the bushell!
Quite frankly, I have not seen a traditional photography product that has created such a stirr in a long, long time! There is definitely a "buzz" - so that part is done - now you have to put the product on the shelves!
Sincerely,
Peter.