I am pretty sure you are right, my Norwegian PAX from 194x has a much smaller pole changer, so I guess this is a pretty much older. I just have to guess about it has been used in a manual exchange, and the last magneto telephone exchange was in use to 1982 or 1983 in Norway, so we were pretty slow on that here. The local makers were not marking their products well, and this one has lost its cover so year and make are still unknown.
dsk