I highly doubt there were only (5) Ski Sporter 16s built in 1964. Walt finishes the final "Plan Overview" on July 1, 1964. It would then take a month to build the wooden plug (July) and then say most of the month of August to build the mold. The 16 was not as complicated as some of the other hulls you mentioned earlier. So on September 1, 1964 out comes 16 hull #1 as shown in the black and white photo below, correct Matty? That leaves four months to build Ski Sporters. I still like the number (10) for 1964 builds but certainly no more than that given what I've pieced together. We also know that two hulls were brought to the New York Boat Show in January, 1965 so those would probably have been built in 1964.