I would just add that, apart from 'tired' hard drive(s) you are going to replace anyway and potentially butchered sled wiring loom, a heavily used empeg might have a slightly (or more than that) burnt-in VFD tube (still usable, but one might find it annoying). They are replaceable, but how easily depends on whether someone has a stock bulk-ordered from the manufacturer (Noritake) at the moment.