1940 S/42, need information please!

[avc.4x4]

Hello,

I'm new to these forums, but have been an on/off collector of guns for many years. My knowledge is limited to various Winchesters and Colts; Lugers are not my expertise. I posted this on another gun board a couple of years ago, but didn't quite get the information I was looking for. I am hoping someone here, who knows these things backwards and forwards, could tell me more about this specific Luger.

So here is what I *think* I have:

S/42 Luger (possibly refinished)

Numbers matching, including magazine with code 154 proof.

S/N: 3312 d

Receiver date: 1940

(2) Code 655 WaffenAmpts and 1 other unknown marking/proof next to them.

So I guess I'd like some clarification on this gun. The extent of my research shows that S/42 variations were only used until 1939, yet I have a 1940 receiver.

Is my gun actually refinished? Certain parts look to have been the strawed finish, but other parts look to be more blue. I have read about the "red-ish" color found on some models, could my gun have this distinction, or would it just be lack of original finish/patina?
What type of value would you place on this specific Luger? I acquired this gun in a trade and have a number in mind what the other gun was worth.

Any input is appreciated, more pictures can also be taken,
Thanks!