What I meant was anything factory-installed that makes your Ruger special.
The 12" Singin' Six was evidently a factory-assembled one too.
It had the Ruger rollmark on the barrel. He had a NR9 convertible that had the same markings.
I never saw anything in any Ruger history books that mention it. I asked Ruger (Southport, I reccollect) about it. They said it was definately NOT built by the factory.
Heck, go ahead and let us know of anything you've done to your Rugers to make them special too.
MG