I think they are the pieces that go on the aft end of the front fenders (towards the top). They have a rubber seal that goes with them.
I can't find a picture in the couple of venders catalogs I looked at.
I know they are shown in the assembly manual. This manual is not numbered however I put page numbers in mine. Assuming that you have one and make page 1 the very first page of the catalog (1953 thru 1959 VEHICLE SERIAL NUMBER IDENTIFICATION) they are shown on page 112 called a filler.
By the way, not sure why a 60 to 66 assembly manual starts with 1953 thru 1959 VEHICLE SERIAL NUMBER IDENTIFICATION.
