Hi!
It´s an Archimedes B-22 from 1955.
The type B-22 was first in the market 1938. It become a strong seller for the Archimedes company, then in Sundbyberg near Stockholm later, after 1966 in Uppsala.
In 1941 the Archimedes company was sold to the Electrolux company which sold it to Monark-Crescent company, therefor it moved to Uppsala.
It is very small differences between your motor and how they looked 1938. The flywheel with the magneto, the tumbscrews and the gasoline tank are the only parts that not
are the same.
The motor is rated at 12 hp and 3200 rpm
It is 345 cc
Cylinder is 60 mm and stroke is 61 mm
It was in production until 1979!!
In the 60´s and later we in Sweden called it “jungle motor” because it was most exported too South America and Africa.
Hoping this will help you a little.

Exactly how many that was made are hard to say, but I have some dusty factory papers. The numbers that were produced between 1950 and 1964 are 32979.
That figure includes all types B-22/PA-120, B-22U, B-22B/PA-120B, B-22C/PA-120C. They were all “B-22” but were even sold as Penta (PA-..). The B-22C/PA-120C. was different in
the lower unit as it was made in brass but cast as a modern engine and with a plastic prop. It was made between 1959 and 1962 in 1697 units.
Before 1950 we can guess at least 5000 maybe more and after 1964 the planned production on an other paper was 7200 units until 1968 and lets say 10000 between 1968 and 1979.
So totally it is about 50000 units.
And yes I have some manuals and advertisements for them.

Anyone would have a spare Archimedes B22 tank and 2 sets of decals?
Thanks