Yeah, I'm sure there are many treasure troves like this out there. Not to mention that many theaters and live music venues/auditoriums/etc. are dumping their old (and often classic vintage) gear. They often time have no clue what they're selling or it's "worth", which can be a good or a bad thing depending on which way they "err". Here's an exapmle--the Arie Crown theater in Chicago (which if you check their website "the theater has been acoustically and architecturally rebuilt". Apparently, part of this process involved dumping their Altecs. BTW, this thread is no longer exclusively off topic. Looking forward to your pics......

Vintage Altec Voice of the Theater A7 500