Would These Postal Cards Be Unitrade Ux83c - Mimeo, Rouletted?

Hey All,
I've come across ten of these Canadian postal cards - all related to the Canadian National Express.

I believe the are the mimeo printed type. Definitely a thinner paper andnot as smooth as the regular postal cards.

Each card is also rouletted at the left edge, but only that edge.

Would this be Unitrade UX83c? I searched online and couldn't find any examples at all. Found one guy on ebay trying to pass off UY84 as UX83c. Lol.

Photo below shows two examples I have.

BTW, I did check - they all have 1953 in the lower right corner.

Those cards are known as Railway Freight Advice Flimsies.
They are private order cards and were the top part of a carbon set multiple form printed for Canadian National and Canadian Pacific.
Unitrade does not list private order postal stationery.

These cards differ from the Unitrade listed #UX83 as the card stock is much thinner (flimsy) and each used card will have rouletting at left. Thats where there was selvedge holding together each part of the form.
Unitrade #UX83c cards were printed in vertical strips of 3 and have the roulette across the top and/or bottom of the card (not the left side).
Freight advice flimsies are listed in the Webb Postal Stationery Catalogue.
The ones you scanned are #RKP212b and catalogue at $2.50 which is the minimum price level in the catalogue. There is a coarse die variation of the card #RKP212c that catalogues at $5.

Thank you for that information! Very helpful!