I doubt you'll find anything relating to specifically CDN production of any year unless you can find some Dupont chip sheets used in Canada, probably not different .... and I seriously doubt the first digit indicates a year in either country, take a
look here, the 7xx series of codes started in 56 and went into the 60's ... if your tag is stamped "41" it's likely the lunch whistle blew just then, there's a 411 [red] and 417 [blue] listed for 53
Bill
