chassis no.2275-65 ex
wishes Jarkki from Finland
Welcome to the forum,
If you search "Serial Number" in the forum search engine the first hit gives a pretty good run down of the serial number schema...but the serial number itself is not much help.
To get the date of manufacture is difficult, but you can narrow it down to a few months using the manufacturers date code on the transformers...google woodward-Schumacher Transformer EIA (Electronics Industry Association) codes for the schema...but it is something like
X is the year of the decade built, for example 1977 will be X=7
YY is the week of the year, so YY will run from 01 up to 52
Speakers have a similar EIA code as do potentiometers and older tubes of this era.
There is some cool old catalogues etc. in the " Downloads and Resources" area of the forum website.