You need to talk to a gunsmith.
Scope mounts that mount on the left side of the receiver using the four screw holes are available from Weaver.
what type of scope mounts do I need
One can purchase rifle scope mounts from websites like Optics Planet, Cabelas, Amazon, Scope Mounts, Airgun Depot, eBay, Talley Manufacturing and Jmecks Scope Mounts.
You will have to have it checked by a gunsmith.
Yes. The top of the receiver is grooved to accept standard 'tip-off' mounts that are available from all major scope-mount manufacturers.
50's or so
It looks like any mount that will clamp to the top rail is good. No gunsmithing is necessary to mount a scope.
You have a Grade I Browning takedown semiauto .22 rifle made in Japan in 1986. Browning offers a scope mount for that rifle, their item #12333. Aftermarket mounts are available from Leupold, Burris, etc.
What is a scope mountYou are a hunter, or new to hunting. After finding the rifle you want and the scope you want, you still need to mount the scope to the rifle. Scope mounts hold the scope securely to the rifle.Getting what you pay forBuying a rifle and scope is much like finding a wife, it is strictly a matter of personal taste. Too frequently new hunters will spend exorbitant amounts on the rifle and scope, but skimp on the mounts. This is a costly mistake.The mounts hold your scope securely and help keep your scope true. If you are willing to drop several hundred to thousands of dollars on a scope, the least you should do is consider quality scope mounts. The rifle is only as good as the person behind it, but the finest shooter in the world will miss if the scope is not spot on. Quality, durable mounts will last the life of the rifle, scope and possibly outlast the owner.How to mount scope mountsMore often than not the gun shop where you buy your new rifle will mount your scope for you at no charge. If you are a do it yourself type, here are a few suggestions.Place the bases on the rifle. Check and be absolutely certain they are straight. Tighten them hand tight with the hand tools provided with the mounts. Put your scope in the mounts. Check your eye relief. This is the distance from the optical part of the scope to your eye. Too far and you will not be able to see out of the scope correctly. Too close and when you sight it in for the first time, you are going to have a black eye and possibly need stitches.Once your eye relief is set and you are happy, put the top part of your mounts on your scope. Place the screws in the holes and tighten. As you tighten the screws, tighten each one a bit at a time to be sure the mount is secured evenly. Before the final tighten, check your scope to make sure it is level. Finish and go sight in!
Contact Marlin
Any reputable gun dealer should be able to source an extension mount for the Baikal single shot rifle. Millet make mounts suitable for the Baikal rifle
I am not familiar with this particular model (427) but I am familiar with Benjamin air rifle. If your problem is that there is on Scope rail to mount your scope then I know how to fix it. Crosman airguns owns Benjamin air guns. Crosman offers a special Benjamin barrel clamp that lets you mount a scope to it. See the link below