ABLE Supply Co. 1918 MACK Railbus Reefer Combine

According to the authoritative "Interurbans Without Wires" by Edmund Kielty, Mack factory production of railbuses did not begin until late 1920 with the Model AB Omnibus/Truck. Prior to that, Mack's only railbus production were two small 3' gauge units for the Uintah and the Silverton Northern in 1905. Kielty does mention that in the 19-teens, some lines did buy standard Mack highway vehicles and convert them for rail use by installing flanged wheels, but these would not be covered in any Mack factory railbus records. It would seem that this must have been the origin of the Able Supply Co. unit. Can you supply any additional info about the unit? Where did it operate? What RR did it operate on? Where/how did you learn of its existence? Geezer

It's mentioned in:

Narrow Gauge & Short Line Gazette March/April 1982

Able Supply Co. 1918 Mack Railbus reefer combine