vintage IH International Harvester McCormick 449 & 450 corn planters manual, original 50s operators book

1950s vintage IH McCormick corn planters Operator's manual for models numbers 449 and 450. Used, worn, spotted and marked up but complete. Back in the day, planting corn was an art form of sorts. I know many old farmers who put a lot of time and effort to setting up end rows and perfect spacing using the row markers and books like this one. Not like today where a computer does most of the work for you!