Thank you David, for the information. Here is a picture of my tripod and I believe it is a different version of the lightened version in the middle of the shot. Now I'm started cleaning it and to remove all the rust and red paint. I found some markings refering to the manufacturer. It seems that it was built by J.C.L. in 1942 and broad arrow.
For the restauration I search exact mesurements for the barrel because the possibility of finding an original barrel will be very small, so I want to make a replacement but therefore I need the length of the barrel. greetings Wally
here the link to pictures
http://brechtsoorlogsmuseum.freeforu...-inch-t12.html