That's my favorite caliber and the year I was born. I'll take it! PM coming! Just kidding there but hope your gun is that early. It would only make a very special .44 Special even that more special.me too but Colt site Ser number puts it at 1957
According to Wilkerson the .44 Special was introduced in the Post-War SAA in early 1958. I would letter it and see if it was actually shipped in 1957 or 1956. You have a very nice pair of 2nd Generation SAAs. Enjoy your Colt SAAs.Those are fantastic guns. but I think .44 specials started in 1958.