A couple of options
Try Rudy at D&R Marine. His website is listed in the links section of this site. Rudy used to work for Oday and bought many of the hull and parts molds after the company went under. He is THE source for parts and advice on Odays.Even if he has it, don't get your hopes up too high. Oday did not invest a lot of effort in putting together owner's manuals for their trailerable line of boats. From the late seventies on, Oday made and marketed the 22, 23 and 25 as a unified product line. I have the "manual" for the 23; it consists of a single, double-sided sheet of paper. Not a lot of information; certainly nothing about construction details or any advice on real maintenance. Since the 25 is very similar to the 23 and they were part of the same line of boats, I wouldn't be at all surprised if the "manual" for the 25 was similar.Having said that, the Oday 25 is a terrific boat. The systems are simple enough that you really don't need a manual (although a wiring diagram would be nice). The only thing even moderately tricky about the standard rigging is the mainsheet attachment. Assuming the boat is still stock, the mainsheet attaches to a trangular plate that is part of the backstay. The plate is attached at one of its corners to a short piece of rigging (about one foot long) that is affixed to a tang on the transom. The backstay runs from the top of the mast to a turnbuckle fitting that attaches to another one of the points on the triangular plate. The third point of the plate is where the mainsheet attaches to the plate. This arrangement is less than ideal from a sail handling point of view (no traveller), but it does keep the mainsheet blocks out of the cockpit and allows for boom-end sheeting. From what I understand, the fixed keel version is pretty unusual. What does she draw?