About four or five years ago when I first "discovered" Axiom, I was also doing a lot of stuff with DIY. One of the items I came across was a blurb about the vendor that Axiom was using, and that they made some very good drivers and were well respected within the DIY community.
I had copies of the research, but when we moved it was discarded.
It took some pretty aggresive digging, but I did come across what seemed to be the 6.5": it was NOT listed with the common stuff for sale, so I was left with the impression that it was a custom design. Axiom was not in any way, shape or form refered to in any way anywhere within their website!
I wish that I could recall the name of the company, but it was a long established firm with a very impressive facility!
I felt, at the time, that if this were in fact the origin of the Axiom drivers, it was nothing to be ashamed of!