Looks to me like someone may have installed that fluted barrel "after the fact".
It appears that the recoil lug (sandwiched between the barrel nut and the action in the top photo) is stainless. I have never seen one that came from the factory that way.
As I stated earlier, If you find a rifle you like at the right price I wouldn't get too caught up on the letter designation. If it has been altered after the factory you'll probably just wind up chasing your tail for nothing. For a while Savage had a "parts finder" at their website that would let you enter a serial # and tell you how your rifle left the factory. To my knowledge this feature is no longer available.

I mean if you really want to, simply follow the features on your rifle as it is now, and then assign your own letter code.
thing is if the price is right and it's what you want then get it. if not then pass and get what you want. I really dont see it becoming a collectable or anything any time soon.
Good luck BHJ