WANTED: Info/Specs for Burstein-Applebee 400 Speakers ???

If anyone has any info and the specs for Burstein-Applebee model 400
loudspeakers, or know any website w/ info, please email
.. Appreciate any help..can't find anything on them. I
just bought a used pair and would love to know specs and maybe from
what years they were mfg.. Based on nice walnut veneer cabs and style
of grill cloth, I'm guessing 1960's? Thanks!