Andrew,
In the early 80's Hank switch from Vox(Bruce too) to Mesa Boogie MKIIc because all the Vox amps they got from Rose Morris quit on rehearsal.
For his solo tours Hank tried some Dennis Cornnell prototypes amps and used the Matchless DC30 for all other gigs.
Then he used the KCP HM amp and also on the 2004 shads tour, in 2005 he started with The PInnacle amp all 3 samples went belly up.
On that night he lent a Fender Twin Reverb amp, and ask a member of the staff to get some Matchless amps...so he got 2 Amp heads and use the pinnacle cab on stage.
On the 2009 tour he used JMI AC30 clones and all had problems at first, thanks to Charlie Hall they could use them after all...he fixed the speaker wires(all where soldered the wrong way around).
Hope this cleared things a little.
Cheers Rob