Nickeled or stainless mag for Model 52?

Last year, I bought a mag for my Model 52 that appears to be either nickeled or stainless.  Has anyone seen these before?  I contacted S&W and they say they've never made nickeled or stainless mags for the 52.  I thought it was a OEM mag because the welding seam looks just like a factory mag.  My theory is that someone took their Model 52 mag(s) and had someone nickel-plate them.  Your knowledge and insights would be appreciated.

HARD CHROMED, LOOKS JUST LIKE STAINLESS. JP

Okay. Any idea what the cost would be for someone to do this with a mag?

YEARS AGO IT WAS $20. CHECK HERE. I KNOW THE STILL DO IT BUT I CAN'T FIND THE PRICE LISTED. THEY DO GREAT WORK. JP

https://apwcogan.com/

Thank you very much!  Never would have thought of that being the finish but it makes sense.