Amazing video from Pete Thorn about Steve's modded Marshalls from the late 80's. It features Steve and Dave Friedman, who rebuilt those amps recently.
Also the video solves a thing that that was confusing me for a long time. In All About Evo section there is info that DiMarzio prototype pickups were called Knucklehead, Panhead, Flathead and Evolution, while on Pogo, the guitar's page it says that one of the prototypes were called Pogos.
So, as it turns out. Knucklehead, Panhead and Flathead were amps. More precisely Knucklehead and Panhead are the Arredondo moded Marshalls and Flathead is a Lee Jackson moded Marshall with square switches.
Knucklehead is heavily featured in this video and going by the info, it was Steve's preferred amp with DLR and Whitesnake (except for a part of EEAS tour where, going by the Journals, he was prefering Flathead, the Jackson amp). Knucklehead is a 1975 JMP Super Lead, heavily modded by Jose. In words of Dave Friedman "As modded as it gets".
So, did Steve recieve Knucklehead and Panhead back from Dave?