Thanks for the replies!
Luigi, it does not have the "0" or the hole in the back of the vulcanite...
I can´t find the serial number of the lens but the inspection tag has two numbers on it. One is the camera number and the second is 34314, might be the lens number.
On page 28 in the Lager book I see a Hektor that looks like mine (except the feet scale) and it has the same type of "f".
Yes, I took the pictures myself: Elmarit-R 90mm from the 1960s on a 5D body.
