Those look to me to be the older gloss Leupold mounts made before they started putting their logos on everything. They are a good strong mount that lets you adjust for windage in the rear mount. I have similar in a couple of rifles. Once mounts are zeroed, loctite one of the rear screws. Then you can easily remove the other screw and twist out the scope. When you replace it, will pretty much still shoot to point of aim. My Rigby was built using such mounts in the 1970’s. It has a full length leather hard guncase that is designed to carry the rifle with scope separate. Under its previous owner - for whom it was built it would travel up to Scotland for the start of the stalking season, the scope would be put on and Mr F would go to the hill. He would check his sights on the first deer and they would be dead on. After many stags later, scope removed, rifle cleaned and back in its case where it would live till the next adventure. All his guns lived in their guncases in his secure study - as in bullet proof glass and vault type door.