S&W is one of the easiest gun companies from which to get many parts. They will restrict a few parts to gunsmiths and armorers, granted, but overall it's often pretty easy getting parts from them. A surprising amount of the time they won't even want to charge for the odd (inexpensive) part as a gesture of customer goodwill.
On the other hand, trying to deal with some of the other gun companies just for parts often makes using one of the aftermarket wholesale/retail companies seem much easier.