I buy spare triggers, hammers, firing pins & so on for the Smiths.
Ruger makes such things much more difficult on their DA revolvers, so I have two 3-inch GPs & three 4-inch GPs.
I cannot possibly run out of functional Ruger .357 Mag DAs during my lifetime, barring natural disaster or un-natural act of man or government, even if Ruger goes under tomorrow morning & never makes another one.
The Security-Six I started policing with in 1976 is an example of a great gun, but also an example of one that Ruger couldn't be expected to keep supporting at the factory level forever.
It sits in honorable retirement; ready to return to use if needed, but otherwise kept as a reserve in favor of the GPs.
For the forseeable future, the GP can be easily repaired by Ruger at the factory or easily replaced by me at the gunshop if it breaks down or gets lost or stolen while out & about.
Can't say the same about the Security-Six family, but they do illustrate that nothing good lasts forever.
Buy whatever spare parts you can to keep that SS going as long as possible.
They are durable, but they do break on occasion.
Denis