Doing a 1984 cab would make sense, but 5150 wasn't even a Van Halen album. 
Bite cher tounge Kremmit.

Yes 84 did rock, but 5150 was probably one of my VH favorites. (Actually it was my first concert too). Actually, those are my two favorite VH albums. Why did they have to go ang get sucky (I am referring to the post Hagar days) That song on the twister album was about the last good thing I heard out of them.
Back to the thread. Don't make the strings part of the art, put real strings on it. It is a cabinet... You have a huge wooden box. With strings on it, you WOULD hear them ring if you tightened them right. You could tune them to a chord. Sure would go out of tune with humidity and all, but doesn't take long at all to tune a cabinet.
Also, I love the idea of a Floyd Rose on there, but use a real one. Then on the underside, place a cherry microswitch and make the trem be your cabinet on switch. My hunch is that there are enough nearly dead guitars with FR Trems that are still in decient condition, you could probably get one for cheap. Just re paint it shiney black. It does not have to be music worthy. Not sure who said it, but guitar Volume knob for cabinet volume was a great idea.
as a side note, I believe that when eddie, went over to peavey is about the point in time when it started to go down hill. Go with the marshall. Heck you could mount 4 12's in there and make a loud as $#!+ cabinet. You get blown up in asteroids and your wall gets taken out (Michael J Fox...Back to the future).