I may be of some help as I owned and sailed a Westerly Padgent 23' for 15 years. These are stout, well built, seaworthy boats. These boats were built to Lloyds specs and hulls were certified by Lloyds (they usually certify large ships) to high standards. Equipment tends to be first rate. Laurent Giles designed his basic twin keel yachts in various sizes. Although small, 22' westerly’s have crossed both Atlantic and Pacific oceans with little problem.
The cabin windows look overly large, I suspect someone has enlarged them. I hope you won’t need to haul her too far on that horrible looking trailer. I think $500 is a good price for the basic hull, deck and rigging. The question is are you up for that much work? I lived next to a marina for many years, it was one of the few do-it-yourself yards around. I always joked, the boats stayed ..... owners changed.
What you’ll end up with is a boat that performs fairly well off wind, but won’t point as high as a mono-keel. She’s tender to the point that the lee keel gets horizontal, then she stiffens up and is very hard to heel much further — takes a huge gust. Because you have two “fin” keels she is rather quick to respond to helm and she can turn in a very tight arc.
The cockpit and cabin are very spacious and comfortable, especially for a 22'er. My 28' Morgan has about the same usable interior space as the 23' Padgent and the Westerly’s cockpit was more comfortable. She’s a quality boat. If you must do a project, working with quality is a plus.