If it was me, I'd go for or something similar to the Australianicon HT snipers, repro mounts are available and you have the option of two scope ring size's too, scope wise I 'd use a Germanicon ZF39, plenty of post war variations of these (I've a 6 x one which will be mounted to something in the future)

I can't remember what needs to be done to fit a German Short side rail mount or long side rail mount, but think it can be done with some tweaking. (maybe a lot of tweaking the more I think about it)