1913 Erfurt finish

Gentleman,


Great website.

Iâ??m new to Luger collecting and this is my first time posting a message. Maybe someone can help. Recently I traded for a 1913 Erfurt with all matching parts except mag. I have found out that it is a rare version with a stock lug. Supposedly it has been refinished. The pitting was filled with bluing and the surface shows a lot of grinding or sanding marks. I read about using Flitz polish to remove cold bluing and after trying it on another gun first, I cleaned the luger with just polish and paper towels. Sure enough it was cold bluing over the pitted areas. At least 90 % of the finish is left and it appears to be rust bluing. So, after writing all this, could this be the original finish even with the rough surface marks? I can send pictures if someone is interested. Thanks for your time.