Hello, I am posting pics of my ANB-H-1 receivers. I would like to know, if possible, if they are WW2 period or post WW2. If they are WW2 period then I will have a use for them. If they are post war then I will sell them. The red plug has "PL 354". The information on the receivers are:

RECEIVER
ANB-H-1
MADE IN USA
BY
UTAH CHICAGO

One of the receivers has the above information but: S/N1597" above the word RECEIVER. Does anyone know what this means?
Thanks in advance.
Are These ANB-H-1 Receivers WW2 Period?Are These ANB-H-1 Receivers WW2 Period?Are These ANB-H-1 Receivers WW2 Period?Are These ANB-H-1 Receivers WW2 Period?Are These ANB-H-1 Receivers WW2 Period?Are These ANB-H-1 Receivers WW2 Period?Are These ANB-H-1 Receivers WW2 Period?Are These ANB-H-1 Receivers WW2 Period?