Public address vintage speaker bar

There's no brand indicated on this speaker bar. It contains 4 aligned 4" alnico speakers that are probablem from early 1960s. These types of speaker bars were generally installed vertically. The supplied brackets are fully adjustable.

-Year(s):Early 1960s
-Retail: N/A
-Type: air suspension
-Components: 4X 4" alnico speakers
-Power rating: 2.5 watts @ 8 ohms (unverified value marked on a home made sticker but possible rating)
-Features: Adjustable rheostat volume
-Extra informations: Flat screws rear connection.
-Size: 16 5/8"(no brackets) X 4 1/4" X 2 1/2" Deep
-Weight:
-Status: In hand