Random thoughts...
Between 1968 and 1978, most bands were using NMV Marshall and/or VOX. As far as hearing Van Halen 1 for the first time... I assumed he was using an MXR Phase 90, MXR flanger, Echoplex into a Marshall; which was pretty much spot-on. Any player in those days would have guessed the same rig. What was unique though, were the elements of compression and attack. More VOX-like than Marshall; which made me think that he was possibly using a VOX + Marshall rig.
After talking with a few people who were involved in the L.A. music scene (who claim to have known Ed), I discovered what it was that he did to get those first album elements. Posting details would only create a category 5 diarrhea storm, so I will refrain from doing so. Suffice to say, playing this type of rig is laborious! Notes don't just pop-off the fretboard like they do a MV amplifier. You're not going to get VH II performance out of a VH I rig... No way.
I always hoped that one day Edward and Randy would share a rock stage together. Ed's virtuosity combined with Randy's schooled exactitude would have been something to experience. Come to think of it, I don't recall a time when Ed has ever shared the stage with another guitarist?