I searched the internet and found this website:
NARROW GAUGE BUILDINGS & STRUCTURES
DRAWINGS AND WORKBOOKS
http://blazeksplan.com/
All sorts of narrow gauges listed:
Rio Grande Southern
Denver & Rio Grande Western
Mills and Mines in the San Juans
White Pass and Yukon
Southern Pacific ng
Colorado & Southern
Gilpin Tram (C & S)
Silverton, Gladstone & Northerly
Sandy River and Rangeley Lakes
BN