Lyman 422 Expert rifle scope with adjustable Lyman scope mount. This is an old scope with straight cross hairs but is still very clear. The base/mount is fully adjustable and made to be mounted on top of a round barrel or receiver.
Scope is 3/4" dia. X 13-1/2" long, base is 4-1/2" long with two mounting holes.
According to an old catalog I have, this scope was made for installation on Remingtons model-12, 41, 341 etc. rifles.