since the trailer is 21.5ft im calling this a flying cloud but could be wrong on it. The rear window style looks like that of the 51, but its a more modern hehr window that most 52 - late 50's use.
But most 52's had a big single pane in back with the 2 small windows sandwiching a big fix pane in front. It also looks like 21 1/2 ft FC's were a thing from 51 and older.
So im thinking this is late 51 / early 52. Could it be one of the first few coming from OH? This is an east cost trailer with alabama plates.
Heres the kicker; VIN / ID plate is missing.