A full-size copy of that basic rigging sheet can be purchased from Rudy at D&R Marine for around $6.00 or so. However, I have "modified" a copy of that sheet by transcribing it into booklet form and added a copy of the 1979 wiring diagram and the optional mast-raising system instructions. I also have added a few details not in the original rigging sheet.
I can make a copy of this for any 25 owners, I can even include scanned copies of some O'Day 25 brochures and magazine ads. ( have a copy of the OMC Zephyr sales brochure with dimensions, but do not have any detailed info on the VIRE or Yanmar Diesels.) I do similar manuals for the Day Sailer II and Widgeon and usually ask for $10 to cover printing and postage costs, at the moment I have less on the 25 than on those other boats so might do the 25 manual for $8.00
e-Mail me for ordering.
PS: I have verbal blessing from Rudy to copy the manuals that I have, actually he provided some of the DS II and Widgeon info. He esentially holds the copyrights to O'DAY.