hey Mark,
was going to say a boost into the Cali might have been the ticket =0 it could certainly get into that territory, but otherwise have you tried say a splawn ? either a quickrod or a nitro, could be closer to what you're looking for
or even a JMP-1 into a marshall power amp rack setup, a lot of 80s bands still use that setup (def leppard to name one)
it might be easier to find a newer production amp than the elusive marshall from the magic year while also maybe being more manageable volume wise, those old amps sound awesome but are crazy loud
good luck in any case =)