Vintage Teacher Valentine Cards Lot of 3 Mechanical Die Cut 1940s 1950s Ephemera

Vintage 1940s or 1950s mechanical pop-up Valentine's Day cards specifically designed for teachers. This charming lot of three features schoolhouse themes, including children at desks and blackboards with 2+2=4 math problems. These die-cut paper ephemera pieces include fold-out mechanical elements and classic mid-century illustrations. Each card has been signed on the back or inside by the original student, adding a touch of authentic history to these collectible holiday greetings. Made in the USA, they showcase vibrant red, yellow, and blue tones typical of the era.  Good vintage condition with minor wear due to age and handling.