drdougrx ,
maybe little late with this , but I just went to Midways web site. They list what your looking for , both to convert from Ruger to Weaver and as odoh stated a base that replaces the rear sight. I've always used the oem system with a scope....mainly cause I can remove the scope and use the irons if need be. Then put the scope back on , and it is very close to the original zero. At least minute of deer @ 50 yds. So on a special hunt when your out in the thick of things and drop the gun.....only a matter removing the mounts to perhaps saving the hunt. Had a friend that used the weaver adaptor style.....couldn't keep it tight....I understand your problem tho. If your not planning on removing the reflex....I'd go with the type that replaces the rear sight , it looks like it would be a better setup.
regards irold