The 18 sketches are by artist Donald McGill who produced more than 12,000 original artworks for the postcard industry between 1904 and 1962.
Along with a pun-filled caption, the pencil sketches include stamped approval by the censorship board.
They sold for between £55 and £220 and fetched about £1,200 in total, auctioneers Moore Allen said.
Described as the "king of the saucy postcard", McGill produced thousands of artworks and an estimated 200 million postcards were printed and sold.
Often with a double, risqué meaning, one of his sketches shows a buxom blonde flashing her bloomers as she waters a flowerbed with a passing man saying: "I like her display of pinks, Fred!"
Another features a red-faced policeman telling a curvy blonde driver with a broken taillight: "You've got no light behind, so I'm afraid I'll have to pinch you."
But in the 1950s, McGill fell foul of a crackdown on the saucy postcard industry and was prosecuted and fined under the 1857 Obscene Publications Act.
Many postcards were destroyed by their owners during the government crackdown.
Original bawdy sketches the basis of thousands of "saucy seaside" postcards have been auctioned in Gloucestershire.