Welcome to the site, Kevin! And congrats on what will be your first machine of many if you are like the rest of us.
The Vendo 39 was the first vintage machine that I acquired. I bought a repring of a parts and service manual and other than it being a nice thing to have to go along with the machine, I feel it was pretty much a waste of money. There are enough people on this site who have worked on 39's who can guide you along the way. My suggestion would be to save the money and put it into the refurb/restoration.
Tim