https://www.kijiji.ca/v-art-collectibles/winnipeg/western-electric-320-rotary-phone/1462696557
"This is a World War Two Western Electric Type 320 ROTARY DIAL EXPLOSION PROOF Telephone. This rare and unique telephone is in good condition - please refer to the pictures and message me with any questions you may have. The front is marked "320 Type Telephone Set", "Western Electric", "Made in USA". The handset is marked "Western Electric Company", made in USA. These phones were used by the military and mining as they were explosion proof. Measures approx. 10 ΒΌ" in diameter x 7" deep. See pictures for more details. GREAT addition to any collection! Very Heavy."
Thoughts on the phone and the price?
Before considering price, I'd want to see more photos -- especially from the back. It's important to know whether the large circular mounting bracket is included, and whether the internal components are still present. Is the handset marked F6?
You might think of some more questions after reading the BSPs referenced here:
http://www.paul-f.com/we300typ.htm#320 (http://www.paul-f.com/we300typ.htm#320)