For Zenith full line release date was sept-oct. So those were in dealer hands the prev. year. SO a 1951 may have been sold in 1950. There can be early
releases also. High end slow movers can get dragged out over 3 yrs.
Best way to date the build is with date codes on unchanged OEM parts.
Find the newest date then add 30-60 days & you will be very close.
Main reason for fall release was as stated, hollidays. World series, football season, Thanksgivings, & Christmas. January prices fell & big sales
to clear off the shelves.
Zenith sold a lot of "kit" TV's in Argentina & I think Brazil. The kits had to
meet a certain " local content" percentage to get around import taxes.
Cabinets were different but the Zeniths were close, you knew what it was.
To save more weight CRT's are also local often.
73 Zeno
LFOD !