Just goofin around and I saw this pic of the front grill that had a WILLYs logo stamped on it. I looked on the Kaiser page and to me, all years from 41 on up seemed to have a non stamped grill. In addition, The grill slots went almost all the way up to the top, so there was no room for a stamping.
TJ is correct as usual! The 3B grill had a raised hood design for the F head 134 engine. The 3B was built from '53 to '64. The raised design of the hood and grill also allow for Willys to stamp their name on the front for brand recognition.