allglock is correct, The pins are not the same, Very different, They do use the same firing pin return spring..
The older style the 042 uses which is also the same as my 642 & 940 has a pin through the frame that holds a firing pin bushing the retains the firing pin that is removed from the recoil shield, were the newer style is simply retained by a small pin under the sideplate & removes to the rear after the hammer is removed or cocked.
Here's a pic of a broken older style pin with the newer pin in the background..
I had to send this pic to S&W to get the right pin for my 940, Finaly I got someone on the phone who would listen & they wanted a pic so I emailed them this..
I ended up with 6-8 new FREE newer style firing pins with this one transaction, They also sent me a return spring & bushing too.. FREE..
Gary/Hk