Wooden passenger cars were still in service well into the '50s in Canada, although mostly on branchlines and/or mixed trains. Your 80' cars would most likely have 6-wheel trucks, very similar to those found under heavyweights of the same era, while the head-end cars could have either 4- or 6-wheel trucks. Most of the ones of which I've seen photos had 6-wheel trucks.
These kitbashed head-end cars were built using photos as a guide, so are reasonably accurate:
These cars are MDC/Roundhouse Pullman Palace cars, but they're very similar to cars operated by the CNR:
And a couple of kitbashed free-lance cars:
Wayne
In the photos posted above, the first two and last two cars shown are former Athearn "shorty" Pullmans, while the Horse Express car was formerly a Rivarossi coach.
On some railroads wood sided head end cars lasted longer than coaches and other passenger cars, for safety reasons. On other railroads they ran wood coaches well into the transition era. And WWII brought some wood cars out of semi retirement.
The concern was more over wood frames and floors rather than sides. It was hazardous to have a pusher behind a wood car for example. Some wood cars were retrofitted with steel frames, yet some of them kept the truss rods
I can recall seeing wood sided cars in Soo Line work train service in the early 1980s. In fact I think they finally burned those cars just a few years ago.
Dave Nelson
Both of the CNR cars with truss rods, shown in the photos above, were re-built with steel underframes, but retained their trussrods. Many of the horse express cars, when retired from express service, had the bodies cut down, and continued to run in work trains into the '90s.