Have you checked here? http://earlytelevision.org/tv_schema...ms_zenith.html

The number you posted is a model number. A porthole Zenith has a chassis number in the format of ##X## where #is a numeral 0-9 and X is a letter A-Z (though Zenith skipped letters that look like numbers such as I and O).
In any model year Zenith would have around 1-4 different monochrome TV chassis numbers and those 2-ish different chassis would go into 100s of distinctly different looking cabinet options each cabinet having its own number to distinguish it. When asking electronic repair questions it's always better to post the chassis number (if you know or can find it) because it's more widely recognized/remembered by those who have worked on one.

Need set 138, folder 7, covering a 1951 Philco 51T-1601. Please contact me via PM if available. Thanks!

I might have one I could take a pic of if you only need the information.

I also have some later SAMS from the 60s and 70s that I haven't tossed (yet). If anyone wants an original SAMS just to have because they're cool, let me know. Anything I have left is available for the asking.

John

Do you have a Sams for a Magnavox T-925 chassis? It's a 13/14 inch black and white portable from the late 1960s.