State Tool & Die
Railroad Privy/Outhouse - (Plastic Kit; C&O Design)

Single Kit
Walthers Part # 661-500, p. 558 Walthers 2012 HO Scale Reference
HO scale, $3.95, currently in stock at Walthers

 
C&O standard design. Features detailed plastic parts and basic instructions. Can also be used as a small storage shed.