Here are the couple of pictures I have taken of it. I posted these on another board trying to get some information on it but never did get any replies. My camera isn't the greatest so they aren't the highest quality.
Its hard to make out in the pictures but it does have the "Zella-Mehlis (Thur)" on the slide and the serial number is 301XXXP. I've found one source that says that serial number dates it in 1943 and another saying 1944. It does not have the "WaA" proofmark but it does have the eagle over the N under the ejection port and on the barrel. The two eagles over N's are the only proofmarks I have found on it. Correct me if I'm wrong but from what I have gathered the lack of the "WaA" proofmark means it was a commercial model.
The parts I called stainless may actually be chrome plated or nickel. To be quite honest I have no idea. I haven't owned a gun in any of the three so I wouldn't recognize it. I am also not certain if the rest of the gun has been refinished or not. If it has it was years ago because, although still very shiny, it has developed quite a bit of wear.
I have found a lot of information about this gun online but there is one other thing about the gun that has me confused. As I said earlier, the serial number is 301XXXP. It is listed on both the slide and the frame. Everything matches but on the slide the third digit, the 1, has been stamped over a zero. Its all lined up perfectly so I assume it was done at the factory but it just looks very odd.
EDIT: It is 32 ACP.