I am building the Smokin' Rockets 7.5" Honest John for my L-3 attempt. I am planning on using rail guides for the 1.5" rail. The guides need to be spaced away from the body tube because of the shape of the nose cone. I am looking for suggestions on how to accomplish this. I normally just glue a block of wood to a centering ring and use a sheet metal screw to attach the guide but am concerned about the added stresses caused by just using a spacer of some sort like a small pipe nipple or a stack of washers.Les.