Unusual Kellogg Wooden Wall Phone

Unusual Kellogg wooden wall phone with not one but two long pole receivers and a strange wooden transmitter box and transmitter mouthpiece cup that looks like an old operator chest set mouthpiece turned upside down. There is a detailed two-station set circuit diagram inside the upper box door and metal dry cell battery holders inside the lower box. I bought this phone several years ago at a small antique shop, and have never seen anything like it on Ebay or elsewhere. If any Kellogg collectors can provide any further info on the phone, I'd appreciate it.