At least 4 sources
Manuals for the DAY Sailer II are available from D&R Marine ($7 for a single 11" x 14" 2-sided sheet), The mentioned web-site (I heart O'DAYs), from Roger, or from me, mine is a 12-page booklet with many diagrams not found in the D& R manual (although Rudy gave me a few of them, so he might be including them now). I also include copies of some of the sales brochure pages from the past.The DS III manual is available from Rudy (D&R Marine), and I think he has the DS I? (I'm still working on my copy of that and the DS III).