De Forest Long Wave Type Radio Receiver R 36 Made for U.S. Coast Guard

I recently purchased at least a dozen old radio and parts of radios from a warehouse find here locally. This De Forest Long Wave Type Radio Receiver was in the mix. I am not sure how old this unit is or what a value of it may be. I think it must be quite rare since it was made for the U.S. Coast Guard. This unit is capable of reaching 2000 to 12000 meters. It measures approximately 16½”x 20” and 11½” tall to the top surface with the knobs it is 13½” tall total. I am not sure what the top surface is made of but it resembles bakelite in color but is much stronger.

Any information is appreciated.

Thanks,
Trenchartman