According to the PYRO model catalog of 1969 they offered the "Historic Sailing Ships" series. There were 16 ships in the inventory, priced at 75 cents per model. Among the ships were the Mayflower, Constitution, Santa Maria, Golden Hind, Bon Homme Richard, Half Moon, Nina, HMS Victory, Brig of War and Barbary Pirate ship. The scale wasn't constant as the Constitution and Mayflower were 6 1/2" and the the HMS Victory and Barbary Pirate were 7" in length. I'm guessing these plastic models date back to the early 1960's, late 1950's.
The ITC model catalog(1963) offered a small fleet of ships similar in size but a smaller selection...I recall building a Viking ship and a Chinese Junk, molded in black plastic.
Hope that helps....
Mike