Hi Tim
Ahh the legendary FM Co. They have the honour of building all of the Cdn carries and many fine truck during the war. Although Cehvy did beat them on the trucks but thats another battle.
FM Co is the stamping code for Ford Motor Company. You will find this stamped on every single carrier part out there. Some stuff is stamped with a circle around it while other simply have FmCo and a year.
All of the Carries built in Canada were made at the Ford Canada plant in Windsor, Ontario.
I hope that anwsers what it was you were asking.