Hi Rob, thanks for the response.
I saw Ed's post, which is what got me thinking about it. I'm certainly not suggesting that anyone infringe on FMI's copyright, but clones abound for many other sought after amps. I'm sure the Sunn name, logo, likenesses, etc. are all strictly protected, but the circuits/designs aren't, are they?
I'm not positive, but I don't know of any legal reason someone couldn't take the schematics for, say, a Model T, build a clone, call it "Super Amp X," and be in the clear.
I suppose I'm just young enough to fear that I'll see the day when Sunn amps are nearly impossible to find or prohibitively expensive to acquire.