It's possible, with a mismatch of numbers like yours, that you have a gun put together by an employee; either legitimately, or possibly by absconding with the parts. The frame is made of carbon steel, while the barrel is stainless. Originally, that barrel was fitted to a stainless gun; according to the numbers on it. That's about all that can be determined based on the information you've provided so far.

Hope this helps, -Deeton