Refrigeration unitwet chest

I have what I believe is a westinghouse wet chest. The letters on the inside od the tub,are W-NAB. That is all I have to identify it. It has a front grill and a cooling and circulating refrigeration system. Does any one know anything about it. Except for the grill it looks like a standard. I have pictures.
I would like to make the cooling sysyem work and need a cap catcher.I have been told this machine is between 1935-38.