A bit steering away from the topic for your intent to selling these miners. But i have some AM Tubes that i have quite a bit of problems running off the crap BE controller. I got a UART USB converter but i can't find a version of already compiled windows cgminer/bfgminer that works.
Might i bother you as to where you got your RasPi image to run these?
I'm not positive I save everything on a computer of things that work the do's and the don'ts so I don't keep making the same mistakes lol. But I am at work right now so I am not positive I believe I got mine off of dogies prisma guide on here. But like I said not positive on that.