Phil Rhodes worked for Cox & Stevens, which changed its name to Philip Rhodes Naval Architects and Marine Engineers in 1947.I actually have what may be one of the first or second (I seem to recall finding and earlier boat) fiberglass production boats. It's a 1961 Columbia 29 Hull#64, they were a S&S design but... guess where Phil Rhodes was working before he went out on his own... So he drew the lines for the Columbia 29 while working at S&S. I know the design was commissioned in 1958/59, and production started in 1960.
I had a Vanguard for a number of years, and I agree with what Jeff H said.