Terry's is missing the plastic cap where the beacon mounts, that is why it looks different. They are both the short fin. On the later models with the tall fin, the leading edge (below the plastic cap) extends well above the main body of the fin. On the short fin, like yours or Terry's, the leading edge basically stops at the same point as the rest of the fin.
Take your foil wrapped plastic cap, beacon, and VOR antenna off and it will look like Terry's.
The taller fin was introduced at serial 15075782 (beginning of the 1975 150M models) All '66 thru end of '74 use the same part number fin.
Charles
Last edited by Chuck_Hanna; 03/22/10 03:33 AM.
