Chapelle lists hundreds of vessels in his book “The American Sailing Navy”. Not sure if any of them appear on Sailboatdata’s site. Perhaps because they’re not really pertinent? There are very likely Russian books about dinghies made in Russia too, and those boats may not show up on Sailboat data either. Until Google gets done with digitizing everything – which may take a while – don’t expect to find everything online. Boats that the editors of your book felt compelled to include in their tome may not have been the big hits that their builders hoped, back 40 years ago.
Taking a different tack, please note that there is also no copyright on boat names. Six different designers could each have different designs all called “Rocket”. They could be built by twenty different builders in a dozen different countries. Some could be trimarans, others foilers. Some could be powerboats. For fun, look up how many “Spray” designs there are- several by just one naval architect. If it is any consolation, many of the dinghies whose prices you mention could probably be purchased now for less, if you can find one.