I have owned my first yacht for the past two years. Things that I had flagged up myself prior to the survey, I had chosen to park and in hind sight regretted as they cost me more money a year or so later. Areas I wasn't prepared to compromise were hull integrity, fixed rigging and engine. If there is no documentation consider it not having happenned. There are plenty of boats on the water some…if not most owned by responsible sailors who are aware that sooner or later they would have to wave fairwell to their pride and joy and therefore would want to sell to discerning owners. The previous owners of this boat I fear, do not fall in this category. Would you feel comfortable sailing with friends and family on this boat especially if it is being put through testing conditions? Would you be able to find a boat of similar spec that carries with it sufficient documentation to help you make an informed choice?
Food for thought! Good luck with your boat hunting.