That serial number would not have been a grip plate cut down from a grip safety. It would be a casting, and often times you could see the casting seam line down the middle of the exposed steel. The part you need would be the same for blued or stainless steel, but if you found one, it might not be a tight fit in your particular frame. If it was loose, it could be tightened up with a little weld blob and some fitting. Heck, the thing was just a "filler" in the grip area: it didn't have a dynamic function.