Update:
Fired up the ESS AMT 3s last night. I added braces in the cabinets, the drivers are all Eminence and the Heil tweets have new diaphragms. The cabinets were wired with Neotech UPOCC copper litz wire.
I was surprised how good these speakers turned out. Slightly shocked actually. The Heils are awesome tweeters, I can see why people like these speakers and they still sell for so much money, even in mediocre shape. My friend has a few grand into the speakers and I think he's doing pretty well. They sound great and and can play loud with good dynamics.