Complex sentence: By 1952 orders had dried up in the United States and the production run was only 99 units, although they were more popular in Canada, particularly with the CP, and orders continued there until 1955.
Split into simpler sentences: By 1952 orders had dried up in the United States, and the production run was only 99 units. The units were more popular in Canada, particularly with the CP, and orders continued there until 1955.