This is going to get ugly. The first thing many folks do when they buy a Ruger MK i/ii/iii/iv is upgrade the sear to get a target grade trigger pull. Many go all out and replace the entire trigger train. (Trigger,Plunger, spring, dis-connector, hammer, mag disconnect bushing, sear..) Some do there own. Many pay others to install the parts. Now Ruger is saying they won't return those parts if sent in. It's up to the owners to make the frames stock before returning.
I suspect there will be ALLOT of MK IVs that never go back because of this position.

BTW: The MK IVs seem to have been suffering from some sporadic issues already associated with the disconnector . More than a few folks have had issues with the hammer not resetting consistently. (One of my MK IV's was one of them.) Ruger has been reportedly sending out new disconnectors on request. ( Unconfirmed) This recall could be a continuation of the same issue or a brand new one.

__________________
Dave