Here are a few links for vintage plans that I have been saving. A number of them have been the inspiration for things I have made. Lots of fun things to re-imagine (Maslow style).
http://www.vintageprojects.com/
Tons of cool plans for a lot of things. Want to build a personal submarine? They have plans for that…
http://www.thewoodcrafter.net/retro.php
This site was a number of the old Deltagram plans available.
This site also has a Jr Woodcrafter section with plans you can cut out for the kids to build (includes a few of the Home Depot wood kid projects).
https://allcrafts.net/woodworking/woodtoy.htm
Good site, mostly smaller toys, but look out for “Spam” that is hiding as legit links (do not go the the “Build a CNC machine” link. (This is a scam from all I read) Too bad as I would have built that.
http://www.packratworkshop.com/lib12.htm
Fantastic site for Vintage plans (I actually purchased the magazine copies of a number of these plans on eBay before finding this site).
This site is mostly set up for Xcarve type of machine, but still some good stuff if you look around.