Unfortunately Mark Abrahamian passed away about a year or so ago. There were a lot of discussions involving him on the Metroamp forum. There were some guys there that had amps modded by him. Maybe that would be a good place to start looking. I believe his amps sounded better than most trying to get early vh tone.
I personally think Mark's amp mods (and his incredible talent) sounded more like early VH tone than Eddie himself does today. If you've never heard these amps, here's 2 quick links:
https://www.youtube.com/watch?v=85sco_gLFas
https://www.youtube.com/watch?v=SaXTPKmMtC8
I would LOVE to see one of these modded amps added to the Axe-FX II.
Also, there's a good discussion of Eddie's early hardware linked into this current thread in the "Axe-FX II Recordings" Forum (Narzugon's playing is amazing here as well).
http://forum.fractalaudio.com/axe-fx-ii-recordings/80693-van-halen-mean-streets.html
In this thread, they discuss how Eddie's cabs were equipped with two G12M's and two JBL K120's per cab. Got me to wondering if this would be a possible future Axe-FX II feature, ie being able to specify what speakers / drivers were installed in each cab (much like we can now do with virtual "tubes"). I realize the interactions of the drivers and cab boxes would be extremely complex, but hey, it's ok to wish, right
FWIW, I've been intrigued with Eddie's early sound since the early 80's. I even researched and wrote a term paper on his influence on "rock guitar" (including equipment / gear) around '85 or '86. If I remember correctly, a Variac was definitely used and his amps were modded to run very hot. Not that this is some earth shattering news, just that it was a lot closer in time to the original sources.