Here is some!
Thanks to Wikipedia! Here are what some Antique Valentine's might look like!
Antique and vintage Valentines, 1850–1950
Valentines of the mid-19th and early 20th centuries
Valentine card, 1862: "My dearest Miss, I send thee a kiss" addressed to Miss Jenny Lane of Crostwight Hall, Smallburgh, Norfolk.
Postcards, "pop-ups", and mechanical Valentines, circa 1900-1930
Advertisement for Prang's greeting cards, 1883