re: the chambonino (Champ Electronics) site, it looks like it disappeared quite recently which is too bad, since there was interesting stuff there (though thankfully some (all?) saved in the wayback machine.
re: environmental contaminants, here's an example of what can happen to a PCB in a chassis (Mesa/Boogie .22 caliber plus) with lots of holes (for venting --I guess the dust got baked on after accumulating?) :
Maybe smoke is something to think about also (cigarettes, smoke machine, spliff smoke, etc.)?
I think old electronics were "tropicalized" (had varnish coating)--you see these old boards with a golden hue over them. Also I think lightning was more frequent in the tropics (Mesas had Varistors ("V130LA20A"?--what I remember from their brochure). Pete Traynor(?) I understood he used to throw his amps off a music store roof to test their survivability. Tubes would break but the amp would still work (after they were replaced). Anyway, might be many aspects to account for to make something that can survive a world tour.