A buddy of mine gave me a book called "The Operation, Care, and Repair of Farm Machinery", 23rd edition. It was published by John Deere and was intended to be used as a text book for Ag teachers. I can't find a copy right date but the logo and pictures of tractors suggest it was published in the late 40's. It's been a real hoot to read and talks about and shows pictures of some implements I have never seen or even heard of. The cultivator mounted planter is one of my favorites as is the disk plow. Fun reading if you should ever come across one. Neat to see what was considered "big" equipment for the "large" farm back then.