I have an opportunity to purchase either of these LNIB for about the same price. I already bought the mothers mag polish and Spegel grips for the 640. I have a 642 for daily carry this is more of a BBQ gun. Which would you choose assuming they are virtually in the same condition and price? I like the idea of being able to keep the 640 looking new indefinitely with a little elbow grease and I worry about the 40-1 finish down the road. I look forward to your opinions . Both are 38 special and I have no plans of shooting .357 out of a pistol this size.
Thanks, Mike

The 640, without a doubt. Nickel looks great when new but terrible when it starts to wear, especially when it peels or flakes. As you mentioned, you can keep the 640 looking new indefinitely by simply polishing out any rub marks or light scratches. I once removed a minor blemish from a stainless J-frame by very gently using a brass bore-cleaning brush, and the result perfectly matched the original brushed stainless finish.

Also, I prefer Centennials without grip safeties, so the 640 wins in that department, too.