Re: 68, 69 or 70...
I don't see where there was a 1959 model with a glass upper? The hull was already one piece glass but I thought the model line up was all wood topped and wood interiors?
I did look at a 1960 Seaway about a year ago, it was in pretty much all original shape as far as I could tell. It had twin 1960 Evinrude v4s, the plexi windshield, and no lighting or instrumentation or switches at all. Just the two motors and two ignition switches mounted on a metal plate below the dash, as if they didn't want to cut any holes in the dash. There were two relay boxes mounted at the stern under the splashwell, one huge old battery, still in it's metal box, and it had rope and pulley steering.
I actually went back a few times to look at it, but never could agree on a price. I was actually pretty surprised at it not having lights, or any electrical system other than the key switches. The throttle assembly was two Shipmaster type twin stick controls mounted side by side to the right gunwale.
It matched the 1960 catalog pics perfectly other than the lack of lights. There were no holes drilled or filled where lights could have been. It had an anchor or mooring bit just ahead of the windshield, and four tear drop shaped cleats, and two rope guides along both sides of the bow on top.
The boat also had an all metal rub rail. The title said 1960, but it had a state assigned HIN.