1970 "Honest Injun" valentine card

I know I had better things to do, but there is something about office hours which makes me waste time in unique ways. Today during my two hour stint in my every messy office, I started combing through a box of old papers which had come down from my shelf earlier in the summer. Its contents included animation elements, artwork, and scrap books from when I was a kid. On the first page, kindergarten (1970) I found this card to me from "Doug" which reads "Honest Injun! Me wantum you for Valentine". I'm not sure how much longer such images were published, I have not yet found any others similar from later years. This "horning" card from the same time period was also a bit amusing.