It was later re-numbered to 3734 by the Grand Trunk Western (GTW), after the GTR was absorbed into Canadian National (CN).

[1][2][3] The locomotive was primarily assigned in revenue service to pull freight and commuter trains out of Detroit, Michigan.

[1] In 1925, following the GTR's acquisition by the Canadian National Railway (CN) and reorganization as the Grand Trunk Western (GTW), No.

3734 was selected to serve as a backup locomotive for President Harry Truman's re-election train, which ran through Michigan.

4070 was purchased by Louis S. Keller, a member of the National Railway Historical Society's (NRHS) Iowa Chapter.

[5][10] In May 1966, the Midwest Railway Historical Foundation (MRHF) of Cleveland, Ohio reached an agreement with Keller to lease the locomotive for five-years and restore it to operating condition, and No.

4070 operated for the first time in over eight years, and it pulled an excursion between Dearborn Station in Chicago and South Bend, Indiana, commemorating the 50th anniversary of the locomotive's 1918 construction date.

4070 ran out of water while in motion; it broke down from poor quality coal; when the excursion's conductors and brakemen's legal working limits ran out, the train had to sit at Valparaiso to wait for a new crew to arrive; while waiting at Valparaiso, No.

[5][20] Unsatisfied with the length of the spur, the MRHF searched for a longer railroad to run excursions with No.

[20] The MRHF approached the Chessie System to operate regular steam excursion trains on their former Baltimore and Ohio (B&O) Valley Division between Cleveland and Akron, Ohio, and with local community leaders supporting the idea, it led to the formation of the Cuyahoga Valley Preservation and Scenic Railway Association (CVP&SRA).

[1][20][21] Chessie System chairman Cyrus Eaton generously agreed to allow the foundation trackage rights.

4070 pulled the new Cuyahoga Valley Line's (CVL) inaugural train from Brookside Park outside the Cleveland Zoo to Hale Farm and Village.

[20][21] During the first operations seasons of the CVL, every excursion train was mandated to be assisted by a Chessie diesel locomotive for whenever No.

4070 suffered a mechanical problem, but as the MRHF proved the locomotive's reliability, the requirement was lifted in later years.

[20] During the first excursion, the fireman was struggling to get the locomotive's Duplex stoker to work before he resorted to hand firing it for the remainder of the run.

4070 pulled two more excursions for Steam Tours while doubleheading with Reading 2102 on the Conrail mainline between Pittsburgh and Altoona, Pennsylvania, and en route, the two locomotives travelled over the Horseshoe Curve.

4070 pulled an excursion train on the CVL while being fitted with a headboard that stated “The American Flyer”.

4070 was removed from service, since Chessie successor CSX had obtained permission to abandon the Valley Division, undermining the CVL’s operations.

Financial difficulties within the MRHF at the time and a stall collapse of the Cleveland roundhouse dwindled work on No.

The smokebox, firebox, frame, running gear, tender and many assorted parts needed major work before No.