It' a sight for such a kind of gun
my Skype: warrelics
It is part of an aiming circle which goes on a tripod (I believe) For artillery. I do not know all the direct gun mounts so it could have other applications. You are missing much of it. You have part 10.
What I have shown is just one version.
Also made in 1941, with no obvious refurbishment mark but you are missing so much of it this means little, but the color is interesting.
Thank you very much