Re: 65 Aqua Swan Boat
Your boat was built by the Aquasport company. Iboats.com has a forum just for that brand. Scroll down on the main forum page until you find it.
That said, those boat manufacturer forums don't get a lot of traffic.
As with most older boats, finding an original windshield is going to be almost impossible, unless you find another boat like yours that someone is scrapping. You may be able to adapt the windshield from some other small runabout, though, so take some measurements and watch Craig's List. I see runabout windshields on there from time to time.
Also, check out the Restoration forum. Lots of good tips in there for refurbishing your vintage boat.