Looks like a vintage Western Electric loudspeaker ('weatherproof') , for use 'outdoors' .
I'd first suggest that you test the coil windings with an ohm meter , so as to know if there is a possibility that the unit can still function .
You'd need to use this speaker with a matched-ohm amplifier , etc .
I don't know the size of your item , so a post about that may help .
Many of these were used for old-time campaining , prior to elections , mounted on vehicles & also ice cream trucks , etc....; these also were used in factories/workplaces/ball parks as a part of 'Public Address' systems .
Value really depends upon your item being fully-functional , for collectors of such electrical units .
Depending on size , assuming it works , - small units ... around $5 to $15 , larger units $15 to $50 , really huge ones can fetch around $200 , sometimes , in my region (Pac NW) .