Nice boat/trailer package and your asking price looks about right. The hull and rig looks sound and I like the trailer with the struts on the rear that keep the lights out of the water.
I am a little nostalgic about this era. I bought a brand new 1966 Sunfish when I got out of the Air Force, car topped it form Dayton, Ohio to Florida and spent several weeks camping and sailing in the Florida Keys. Lots of fun after a rather stressful 5 years in the military. The Sunfish in the mid-1960s were well built and have held up well. The were a few pounds heavier than today's boats, but the decks didn't crack and the hulls didn't leak if they were well maintained.