Osram 80W MBW/U Lamp

Here is a lamp I never knew existed; I was unaware blacklight lamps were made below 125W, but here is an 80W example courtesy of Andy (Photonicinduction). I am not certain of the date, I can see what appears to be 'PC' on the top etch above the word 'OSRAM' which comes back as March 1958, can anyone confirm if this could be correct..? There are additional markings on the cap (see bottom right image) but these are indistinct. Sadly, the wrapper is in poor condition, but as much as possible of it will be salvaged and a new one made.