My f4.5 135mm Tessar cells are in the UK so I can't check, but I think that the thread is smaller than 40.5mm which is the filter thread size of my f4.5 T coated 150mm Tessar cells that I swapped them with. I'm sure when I bought the lens with a Crown Graphic it came fitted with a 39mm--58mm stepping ring for filters. Both front cells are 42mm OD, and fit rim-set Compur/Coplal 1 shutters.
Trying to eyeball it with a ruler it looks like 39mm is correct for the filter threads. This is for the rimset Compur version 135mm f4.5.
I am stupid or its Sunday. I cannot work out what size lenshood I need for a 135mm Zeiss Tessar 4.5 lens from 1930/1. It is not here yet, so I cannot measure it.
Is it 42mm push on or 52mm, can't work it out even from literature.....duh
It is possible it may be neither. Some German lenses actually used the Eastman "Series" threading.