I have two (2) S&W stainless steel ambidextrous safety decocking levers for sale. Both are complete and utilize the detent and spring that is currently in use in the semi auto you are now using. These should fit any traditional double action 1st, 2nd or 3rd generation S&W autoloader such as 4513, 5906, 6906, 669, 3913 etc. If you are unfamiliar with how to change these out, instructions are available on you-tube or I'd be happy to walk you through it. $70.00 each shipped.
I have one other stainless steel decocking lever that uses the screw to secure the right side lever instead of spring & detent but do not have another s.s. lever for it. I can supply a blue lever with it but it just doesn't look right in my opinion although it would work perfectly. $55.00 for that one.