Not sure if this helps but my 73 Q code has a D3 air cleaner part number. Here is a pic of what the air cleaner looks like. I am not home to take pic of the whole part number but specifically remember it started with D3.
I woud agree with the other comments that you currently have (or had) a 71 air cleaner part number. Here is a picture of a 73 air cleaner from a May 73 production date 180 mile original convertable. I am confident this is the correct part number for the 351 2V with AC.
Jeff, It looks like from your picture the part number is still visible on the air snorkel bout 1/2 way down. I know you will save that.
+1 on both comments. You have 71. The 73 models will have a groove for the end flex hose that is stapled on. 71 had the end flared out which made it impossible to mount an end hose. The 73 flex hose turns down to the cold air intake duct that extends under the battery. The duct is made up of two plastic sections. Basically one is vertical and one horizontal.