Bowser Manufacturing Co.
N-8 Center Cupola Caboose Kit

Penn Central
Walthers Part # 6-56319, p. 202 Walthers 2012 HO Scale Reference
HO scale, $29.95, not currently in stock at Walthers, Expected: Unknown

 
Bowser easy-to-build kits feature plastic molded bodies, underframes, brake platforms, brake wheels, coal loads (where appropriate), free-rolling trucks, nonmagnetic wheels, x2f couplers. Other features include authentic painting and printing, and coupler pockets that accept Kadee #5 couplers.