Roger MacGregor is the Henry Ford of sailboats. Yep, it looks like you have hull #4. Venture 24, no pop top, became Venture 224, pop top in 1972. You have one of the earliest 224's. Vintage. Venture 25, Our Freedom, same hull, different top mold came out in '75. Macgregor 25, modified hull, different top mold and interior came out in '78. and so on...Friend of mine had Venture 21 hull #8. V8. First production boat by MacGregor was Westwind 19, early 60's. Built some Venture 17's. and Venture Cat. Also 36 footer. Sadly no more Macs. Plant in Costa Mesa shut down as well as Catalina Plant in Woodland Hills, Islander and Cal in Costa Mesa.