Front bumper brackets: 1938 standard & deluxe & pickup, 1939 standard & pickup.
Bumpers same interchange, same front and rear. Rear brackets (pickup only) are the same 1938-41.
Further information... I received a pm questioning my information. I was partially correct. the January 1939 parts book shows the SAME bumper, however it shows different front BRACKETS. My experience in selling parts has been that the two are close enough to work.