I really appreciate all the opinions and suggestions my question provoked. It has helped me define the problem and reach a tentative solution.

I realize that the depreciation in resale value resulting from altering an otherwise original weapon is not the factor which troubles me about adapting a rifle not otherwise designed with scope use in mind. For instance, I have an original unaltered M1910 Ross rifle in .280 Ross for which I have tried for years to come up with a solution to the problem of mounting a scope on. The thought of drilling and tapping the action does not concern me in the slightest. Without a scope, the rifle/cartridge combination simply makes no sense.

I have several pre-war Winchester Model 70's, which are not drilled and tapped on the receiver bridge. Drilling and tapping them destroys their collector value, but fortunately there is a solution in the form of the old Sisk mount, which uses the receiver sight mounting holes to secure the rear base, thus obviating the need for an alteration.

With the BRNO, what brings me up short is the handsome knurled receiver ring with the BRNO logo centered in it. Aside from the fact that drilling and tapping the receiver ring would be like defacing a painting, placing a scope mount base over it would obscure a really striking feature of the little rifle.

I was faced with the same problem with a Mauser Type C sporting rifle with the inscription WAFFENFABRIK MAUSER OBERNDORF US1906 on the receiver ring. Here the solution was obvious. The rifle had already been fitted with a side mount at some point in its past, and the bolt altered slightly to accomodate the scope. The wood which had been removed on the left side of the action had been neatly replaced, but it was clearly not an original rifle.

Nevertheless, I did not want to obscure the markings on the receiver ring, so the solution was a trip to Griffin & Howe, who fitted a vintage G&H mount with windage adjustment to accomodate a vintage Unertl hunting scope with non-centered reticle. I suspect that the same solution will apply to my BRNO carbine.

By the same token, my Niedner Springfield in .35 Whelen and my Hoffman Mauser in 7X57, which are both fitted with Lyman 48 receiver sights, will never be altered for a scope mount, nor will my Type S Mauser in 9X57. My warped sense of aesthetics won't allow it.