The modern CN "noodle" logo was introduced in 1961, that's 13 years before your modelling period. I've seen lots of cars running around in paint 20+ years old so it's certainly plausible.
In fact I've seen old open hoppers in company ballast service in the same era paint scheme as that slab side in the 2000s.
http://canadianfreightcargallery.ca/cgi-bin/image.pl?i=cn300060&o=cn
Yes, as CV acr says, but the number would have been changed to the 321xxx series...
That's true. CN did a fleetwide numbering system upgrade around 1966 or so. Hopper cars (including covered hoppers) all went into the 3xxxxx series, the 1xxxxx series was were all the gondolas went.
Reefers and insulated boxcars were 2xxxxx, boxcars to 4xxxxx and 5xxxxx, flatcars were 6xxxxx, automobile cars were 7xxxxx, stock cars and woodchip cars were 8xxxxx. The only 9xxxxx series cars I've seen are company diesel fuel tanks. Work equipment was numbered from 10000-99999.
I did not even look at the number on the model earlier.
Not entirely...
There were cars delivered in the 135xxx series and they were renumbered in the mid-1960s into numbers in the 35xxxx range.
The modern CN logo was introduced in 1961, so there is some overlap.
That said, the numbers are inappropriate for after 1970, so depending on the re-weigh dates that have been printed on the cars, which I can't see from the model photos posted...
Here's a pair of late 1960s renumbered examples, this is exactly what you'd be looking for:
http://freight.railfan.ca/cgi-bin/image.pl?i=cn352100&o=cn
http://freight.railfan.ca/cgi-bin/image.pl?i=cn355055&o=cn
So I could probably get away with renumbering the older TLT like in the second photo you posted?
Thanks.
Renumbering adds a cool element, and personalization. Microscale makes the red lettering sets for extra numbers. You may even want to do an OCS sand service car...
Those black squares also listed built and/or rebuilt dates as well; because all of the build/oiling/maintenance information was put in there, the proper term for the block is "consolidated stencil", but "lube plate" is also a term you'll see very commonly.
Decals for those bits are available from several sources. Highball and Microscale both have them.
Here's a link to Highball's sets:
http://mgdecals.com/Accessory_Decals.htm
Lube plates did start showing up in the 1970s, but the style that is on the boxcar in the photo (divided into 3 sub-panels) is the later style that came into use in the 1980s and is still used today. The earliest style was a large single block. For the 1970s, any cars would either not have a consolidated stencil yet (probably the majority for older cars)
those are ACI labels and lube plates, the ACI labels were in use until 1978 (I think) and lube plates started showing up around your era. If I were you I'd put on a ACI, but leave off the lube plate...
ACIs were a computerized car tracking scanner tag, and lube plates are a painted area that lists the greasing/oiling of certain components, when and where.