Robert Stears is correct.
Precision in their S scale catalog offered part 19168, C&S pilot beam and long pocket for snow plows, but I've never seen a Precision listed part number for the actual Butterfly plow.
Overland imported their C&S #9 (both runs) and C&S number 60 with pilot plows, complete with flanger lift mechanism on the pilot deck. They imported a few extra pilot assemblies for both versions, in Sn3 scale and On3 scale, around 1990-1991. These show up occasionally on eBay.
Be aware of the construction flaw in the pilot/plows: The pilot beam and plow are only attached to the locomotive via the thin etched pilot deck. The heavy castings are attached to the pilot deck by solder to the inside top of the end beam. If bumped, the solder joint will bend and pop loose and you will have a detached plow and pilot beam assembly to decorate your roundhouse scene!
This event is especially disheartening if you've finished painting and finishing a locomotive with the plow. The only way to repair it is completely strip the pilot/plow and deck assemblies and re-solder, repaint, etc. For this reason, I've decided to replace the pilots on my number 9 and number 60 with standard (summertime) pilots.
I have an extra plow/beam assembly and pilot deck from #60; typically, they are in two pieces and will require re-soldering. I was considering listing the pieces on eBay as is. Contact me off line if you're interested.
Jim
Jim Courtney
Poulsbo, WA