Alan P is correct.
The Weaver highway trailer is appropriate for about 1955 to early 60s. 40 ft trailers were legalized around 1958 but it took some time before trucking companies and RR's purchased them and added them to their fleet.
Just prior to that 32' and 35' were most common.
The website "Hank's Trucks" has plenty of period photos of trucks and trailers.
The CF logo is OK for about 1959 and on until they closed shop in 2002. Although, CF used doubles (24' and 26') about just as much as longer trailers. If you aren't fussy about correct trailer length, the Weaver trailers are good for late 50s to today.
I worked at CF's (Corn Flakes) York PA terminal during summers while in college so I saw these trailers everyday.
One thing about 1950s semi-trailers. Like every emerging industry, there were alot more trailer manufacturers then with each having their own look. Noteworthy distintions were the trailer sides in terms of number of ribs and whether vertical or horizontal or no external ribs at all. Most trailers had squared off noses by the mid-1950s.
RRs that still had plenty of the shorter trailers by the mid 1950s that still had plenty of life in them we used for local deliveries and not TOFC duty. So they were seen at local freight terminals for local pickup and delivery.
One thing everyone should be mindful of is that before deregulation, trucking companies had to buy rights to serve certain parts of the US. So if you want to be absolutely correct for the 1950s and 60s one would need to know where trucking companies were allowed to operate. For instance, CF operated between Chicago and the West coast by the late 1950s. They did start to operate in the East coast by then but under different names such as Motor Cargo through acquisition of other companies; hence the name "consolidated" freightways.
Also again with an emerging industry, there was constant change in company buyouts and mergers with changing logos, etc. So a topic that requires a little investigation to model correctly.