Up the Chastity Belt(1972)

A funny thing happened to Lurkalot, serf to Sir Coward de Custard, on the way to Custard Castle. Lurkalot sells lusty love potions and rusty chastity belts in the market place, but on this day Sir Graggart de Bombast arrives to sack the castle, and to get the lovely Lobelia Custard in the sack! Lurkalot must help Custard cream the knight in pining armour...