The simple answer is yes. The rectangle nut clip was specified, 359791-S2, for 64 thru 66 for both upper and lower bumper guard retention, upper on the guard, lower on the frame rail. That nut clip has a 0.093in panel grip (other similar ones had a 0.064in panel grip), but the supplier, for what ever reason, was changed and all the replacement nut clips had a round design. These were originally supplied by Pal and Tinnerman (now the same company). I don't know when this happened (I think sometime in 1966), but it looks like the assembly line substitute could be 379831-S2 (or one similar) for 66 which is the nut clip used on the front lower valence ends. Replacement bumper guards (NOS) included the round design which may explain the two styles you have. You should be using the rectangle types in both top and bottom for 1965. Unfortunately, the rectangle nut clip is not reproduced and is not available.
Jim
