Dan, I really appreciate the enormous time you put in for the benfit of the slant community, and I really, really appreciate the time you spent on this thread alone. But, lets beat this dying horse a little more.

I looked in Summit's catalogue. and found two styles of stainless brake flex line. Russel and Earl's make DOT ready-made lines with specific appications, but with no listed specs. This makes it difficult for me to use, since my application is custom now. These pre-assembled units must have crimped ends, because they are listed as DOT approved.
Earl's sells exactly the part I need, but it is pre-assembled AN fittings just like I have here. However it is just the hose with AN fittings on each end, and not the final end fittings which are extra. These extra end fittings I have already purchased, so if I purchased the Earls AN style hoses I would not be throwing away half of my purchse to date. The thing is, since they are not crimped, they are NOT DOT. However, they are said to be pressure tested to 4000psi. For what it is worth, the Earl's lines do have a molded in plastic strain relief at each end.
This must mean that they have tested a prototype, and then made the others the same, correct? Which means any hose I purchased from them is not actually pressure tested. However, I can assume it is properly assembled, which I cannot be as sure of in my home made assemblies. Although, after working with these parts, the design is such that I do not see how they can fail, other than the teflon cracking. The fitting creates a really, really solid connection. The entire metal, outer fitting would have to split down the side for things to come apart. If they are properly assembled.
So the question is, Dan, would your concerns be satisfied by the Earl's preassembled AN flex lines. If not, I will keep searching. If so, that would simplify the re-engineering process a great deal. The money is not the important part. It is just going to take time to figure out what part to use now, and then wait for it to arrive.
As a matter of intellectual probing here, does it not seem that these Aeroquip brake fittings would be off the market if they were dangerous? It seems as if the lawsuits would remove them from the market. There is no warning on the package that they are not DOT approved, which means lawyers have not gotten into the act yet in the packaging department. This might suggest there have been no law suits of consequence so far. Maybe there is some broadly understood precedent case that covers all speed parts by implication, or association in some way.
Heck, you cannot even buy a hammer anymore without instructions telling you not to hit yourself, or anyone else with it. Wear eye protection, etc,etc. The first five pages of any instruction booklet packed with every consumer product is lawyer speak, in five different languages saying "you are on your own here, and your future death will certainly be attributable to your lack of understanding, and failure to read all the fine print in this booklet" "WE (the company in question) are hereby off the hook". Why do you suppose the speed parts industry does not have this kind of defensive lawyer involvment in the business. This is not a rhetorical question. It is interesting, is it not?
Dan, I know "Do It Yourself" is DIY, but I have heard mechanics for years use the expression DYI verbally. I just assumed this was some sort of universal mechanics' dyslexia. Of course I am dyslexic as hell when it comes to typing. I have inverted more letters than you can "hsake a tsick ta." So I would expect you to think I had just mis-typed.
This entire suspension, brakes thing got started because I figured out I was having handling problems that resulted from the brake calipers, interfering with the sway bar tabs in semi-hard turns, only when the wheels left the ground, as in bad bumps at highway speed into an interstate exit. It all looked fine while weight bearing, and on the ground, but everthing got real dicey when I hit that bump just wrong. This left me not wanting to drive the car on the interstates, which means no long distance trips with it.
The solution was to swap the spindles side for side, and put the calipers on the rear of the spindle . Easy enough, but these parts are big, and close to the LCA, and even after shaving away offending extra metal between the shock mount and the large rivit that holds the ball joint mount casting, things were still tighter than I liked, only on extreme extension of the suspension, against the stops. So, I started looking for flex lines with a smaller banjo fitting. There you are. If I could go into a store, and rumage through parts bins, I could find what I need in short order, I am sure.
There are always 8 good ways to do everything, and hind sight being 20-20, I likely could have fixed things more easily by buying an upgrade kit for bigger rotors, with caliper adapters extended out further for the larger rotors. This would have placed everything maybe an inch further from the LCA. I might have still had to move the calipers to the back, but it still would have allowed more clearance. I don;t know if 15" wheels would have cleared bigger rotors. The fact that this engineering process never ends is what makes it fun, and even my wife, after 40 years (6/23/1968), bless her heart, truly understands the joy I get out of this process, and heartily encourages it. She no longer asks, "why do you need a new one?" ,(of anything car related).
Thanks for being willing to read this long post, and kick this around a little more. Things are never as simple as "this is bad, and that is good". And, just because a person has an agenda to sell something does not completely undermine it's integrity. It just means you need other opinions, and maybe a little more background. But that does not, in and of itself, make it bad.
Sam