Ok...Ozz, now that you've accomplished the instruction part, lets start adding 2+2 to get 4.
" No Specs"
In case you missed it, there are graphs on the flyer! From top left working counterclockwise, we have the "wave flow" graph (another version of the frequency response graph), the impedence graph (self explanitory...I hope), and another, more typically seen frequency response graph. No, things aren't spelled out to what you may be accustomed to, but they are nevertheless specs. You do know how to read these specs, right Ozz?
"No dimensions, no weight, no driver details, no design details"
Ozz...I think you got me on this one, but it was done this way for many purposes. Heres one that comes to mind...so people, probably like yourself, won't attempt to clone it. Even if you had all those things, theres a high probability you won't get it right. But the obvious does come to mind...its a flyer not an autobiography.
"not even information on how to buy the damn things even if I wanted to"
Once again Ozz, you didn't read. See the part at the bottom that says "Buy you ITZ-4 factory direct on Ebay or visit our website." In case it didn't don upon you, you were on the site when you found the flyer. Since you didn't read that, you probably didn't read the other tab from the home page that said "contact us". This point is where we, again, put 2 and 2 together. Wanna ITZ-4, contact the site and ask for one!
The site may not be complete, hence the "under construction" posted throughout (another 2+2 moment...quick thinking cap Ozz). However, contrary to what you think, everything you need is there. And of course, have a question...contact us tab. :0 Since you've aqquired such interest and intrigue, check periodically to see if the site is up to "prime time" status...and keep us posted, will you?
OK...I make it any simpler, I'm gonna have to take away your tube owners license. ;)