On my boat #107 the mast is held to a 1/2 inch aluminum plug with two screws, one on either side of the mast. However, because I wanted to be able to rake my mast farther forward downwind I had Buzz Ballenger make me up a one inch thick plug which I bolted to the original 1/2 inch aluminum mast base plug and stainless tabernacle? (the hinge) so that now my plug extends into the mast 1 and 1/2 inches. This allowed me to remove the two screws without fear of the butt of the mast jumping off the step. Now the only thing restraining my forward rake downwind when I ease the backstay is tension on the aft lowers. In light or medium air I slack them off quite a bit to permit more forward rake with the spinnaker. It seems to work okay. I'm not sure how much more speed I get, if any. Anyway, it would be a fix if you are worried about your mast jumping around. You could make one yourself out of aluminum or a piece of strong plastic.