Meyer Gorlitz Primoplan 1:1.9 f=5.8cm is normal prime lens for SLR cameras.
Uncoated and marketed as a fast, low light lens, in its day it was a star performer. My version from 1942 was coated after the war, likely in Netherlands by Old Delft. It is very sharp, noticably sharper then the post-war 1950's version - which is still a very good performer.
Of note, the filter size is a very odd 39.5mm.
Links to online resources:
Posted by: Richard Wright Date of publication: 17.07.2017