Well, the good news is that it doesn't look refinished to me.
Personally, I like the Interarms bits, but that is because I have an interest in the company history and their ties with Mauser.
Import markings indeed devalue a pistol (although personally I don't care much, it just adds to the history, if applied properly at least and not by Bubba with a chisel
).
It is a nice representation of a wartime P08 that was resold onto the commercial market in the late 70s, early 80s by one of the largest surplus dealers on the planet in those days. So keep the Interarms stuff with it and enjoy it for what it is. At least it's real and I surely wouldn't feel ashamed having it in my safe