Well the war-time trial reports and instructions to return the rifles after completion to the officer who dispatched them to the trials are excerpted in the neat little book called "without warning". There are contemporary? photos of the bushings which were used on the Lyman Alaskan scope, which was reported to have light gathering abilities superior to the comtemporary No32 scope.
Without referring to the book, I believe that you are correct in pointing out that the bushed mounts were rejected as a solution, along with the Weaver scope.