Howdy,
I can provide some info on the B-18. I worked for WSW from 1966-1985 and built these stoves and have an old one.
This is a later model, meaning it was put together with nuts and bolts. Earlier used rivets. Earlier door panels were most likely yellow, possibly white porcelain but also could have been black paint as were the later. The later body may or may not be 1 piece wrap around or 4 pieces-2 ends, front and back. The door handles on the earlier models were wire wound, not 'T', with the oven handle being a lift up and the oven door hinge spring loaded. Also the thermo was in a nickle plated housing.
Also this may or may not have asbestos insulation liners inside and on the bottom. All earlier models used asbestos.
New price back '70-'80's was approx. $1800 +/-
