I have a fairly decent amount of vintage valentines since my mom gave me all of hers from 1960's elementary school years. Above are just a few.
This is my favorite one from her collection. Several years ago I used some of these valentines to make these valentine cookies:
I also buy vintage valentine stuff from flea markets and antique malls. I really like this uncut booklet that comes with envelopes. It's a DIY kinda thing!
Lastly, I have about 25 valentines from the early 1940's. Here are a few:
The Ho-Beau is so cute!