thanks for your replies. i did find the lansing heritage site and have uncovered a little more info. these were taken out of the stanley theater in pittsburgh PA, which was a venue for stage shows and rock concerts as well as a movie theater, so i'm guessing they were not originally intended for home use. i haven't opened the cabinets to look at the speakers themselves, but will do so to get an accurate date of manufacture.
my biggest question is what would be a fair price for them? does $600 seem too high/low?
will check back later to see if anyone has any thoughts...
thanks again