+2 Fake tag for sure . Like Ed noted , look at the circle R , it's a "P" , not an R for registered trademark. This would NOT fly at Ford . Just like the Shelby America vin tags. There is a guy in Fla that has nice repop FoMoCo tags for sale. I've bought a few.
Like Dan and others I have never seen a legit S1MS or S2MS carb tag in all the years I have been doing this. The carburetor was initially supplied to SAI not Ford and the tag was a Ford deal only. It is my opinion that the lack of a call out for a tag continued on after Ford put the parts into their system after '67. Ford Parts and Service Division didn't have SAI parts until AFTER SAI ( LAX) closed.
Cory ,
Your tags for the 3360-3361 are a bit different than the more common FoMoCo tag. They are genuine for sure , no doubt. One of my three has a tag like that and the other two are the more common style without the "boxed" areas around the numbers.
Randy