Most of what I've ever found on the narrow gauge is mostly
CD 126 and
127 Brookfields in the typical blue aqua glass. Found a whole 126 on Marshall Pass many, many years ago. Haven't found a whole anything in years, but have seen a lot of identifiable shards. I've found parts of Hemi 42s on Cumbres, but those were obviously late replacements for the originals.
The Utah RGW line was much more interesting - supposedly
CD 130 Cals west of Mack. I know a guy who's walked most of the old grade (the wandering pre-realignment into the canyon) and has found lots of shards but no whole pieces. As for me, I've never even found an identifiable piece.
And for those of you who aren't insulator collectors, I'm sure that read as pure jibberish, so I've at least linked the CD numbers (basically style identifiers that collectors use) to pictures.