I have a vague recollection of the main vertical tube mounted on our SC. I know there were two small angular brace tubes off the larger vertical tube the umbrella slid into. These braces attached to the right side foot plate at 90 degrees from each other I think but I just cannot picture how it all mounted up. Its been a long time, 40-50 years or so, and I really wasn't paying that much attention of how Dad did it either then. John, Loren, Tom, et al...??