[rotorwrench]

In the old 1952 Mercury parts book, they used the 1M-9080 for the 1951 but listed it for the 1952 as well. The 1951 cars used two of them. One for the floor of the trunk and one for the filler box. The 1952 and later only used the one since the filler pipe didn't go through the floor. The part number likely changed later since that version was a little larger and was used up through 1956.