Model 99C series A

Been a long time fan of the 99. Bought my first center fire in 1970,a very lightly used 300 Sav.that was about 20 years old at the time. Foolishly I sold it in the early 90's and have kicked myself many times since. Fortunately I still know where it is and have been working on the guy to sell it back to me. Alas I could not wait any longer so I purchased a nice 99C series A in .308 today. (S.N. C 036153) I have 2 questions: 1: what does the series A signify? and 2: what year was it built? Not as classy as my .300 was, but for now will do.
Also just found and joined this site today so it has been a good day!

The Series designations were just the factories way of keeping track of small parts revisions over the years. For instance, maybe they changed the angle of a bearing surface in the trigger group or the size and weight of an internal spring. To you and me it means nothing. To today's Savage Arms it means nothing (cuz they won't touch it). To the folks that worked there back in the day, it told them what version of a part or parts to use if it ever came in for repair.

And before you ask, no there's no records anywhere that anyone's ever been able to find that details what changes were made to a given model when it was assigned a new Series letter.

As for the date of manufacture, I'm going to go with mid 70's given the C prefix. Savage started using the letter prefix in 1968 to denote those guns made after the National Firearms Act went into effect the same year. They didn't change the letter every year like some others did so there's no real way to tell. If there's a stamp with a number and letter on the front face of the lever boss that can be used to pinpoint a specific year.

I just picked up a Savage 99 in 30-30. What is the best way to research the date of manufacture?