I'd LOVE to see some West Coast Carter Brothers duckbill cars - along the lines of those David Fletcher did for his MasterClass.  It seems like just about everything produced for the narrow gauge market from HOn3 to On3/On30 to large scale is almost always based around Colorado prototypes, and with the possible exception of Maine 2-footers, very little being produced for narrow gauge elsewhere.  The west coast was full of narrow gauge (and so was the east coast), but if this is one's preference, he's kind of out in the cold and has to build it himself - especially when it comes to rolling stock.

I think On30, in which Bachmann has been VERY successful, shows that there's a place for non-Colorado prototypes - not the central and southern American stuff Bachmann seems to have (or at used to have had) a preference for, but American prototypes from areas other than Colorado.  As On30 has demonstrated, there's a lot of free-lancers out there that don't want to model the D&RGW or the C&S or the RGS.  MHO.