Pete--
I guess I missed your post of a couple of weeks back!
My tugboat's cylinder cocks are the cone in cone type as you have. Mind you I do not tend to use the tug as frequently as the trains but they have served well enough. I am sure they came from the Stuart turner catalog of the day 1994 (ish)
your seat mate was correct, I design kayak kits for a "living." my own website for the kayaks is
http://www.shearwater-boats.com here is the link to my tugboat
http://shearwater-boats.com/opermodl.html