I couldn't even see what the picture even is.
But I once made a scope mount to hold a Weaver Rail mount - for a old Stevens 22 rifle out of a piece of heavy stainless steel.
The rifle was drilled for side mounts and is very old and nobody made a mount for it anymore.
By notching the holes in the plate, and adjusting it up and down until it got it as parallel as possible to the bore. It worked for what I wanted it to do.
At 50 yards, it would put 10 shots into a area of the bulls-eye that you could cover with a thin dime.