Just was wondering if these signs could be dated or why federal had different stamps so far I've seen 4 different federal electric stamps on these signs. The 4 different styles in the pictures attached.
Maybe someone know s something and could share
Also mine has a number stamp 2-9 I'm assuming 2- 1949
Thanks in advance

ra1016-265666_2.jpg f123fd53bec82038ea253114e1388603.jpg s-l400.jpg phillips-66-1950s-48-neon-sign_1_1d5b9d68d826308d5f046903545a6351.jpg