99.999% sure that it's a BRNO Model 4. I have two of these and both are great shooters. Hope to post some pics when I have a chance.
Mike
View attachment 978352
Don't know about that. The sight looks identical to the one on my Brno Model 3 Target Rifle, and that dovetail would be way too wide for a standard sight.
Could we have a shot of the bolt, particularly the safety?