You could go here and check out all G/C models in the brochures ...
Carlsons ...
http://www.cgoamn.com/40.htmlGlastrons ...
http://www.cgoamn.com/12.htmlHistory of G/C ...
http://www.cgoamn.com/5.htmlI don't own one and have never even seen a first year CV16 or had a ride in one so... this is second hand info ...
The first year CV16's only came in green or apricot (orange)and didn't have a windscreen according to brochures, which can be wrong.
Deck might have been changed the next year for the addition of the windscreen but hull should be the same as latter years until model was changed to a CVX16 (1977)and got a pad.
Hull is made for speed but shallow V isn't great in rough water. Boat weighs about 566 lbs which is pretty light for a 16 footer, a GT-150 is listed at 585 lbs and is a foot shorter and 6 inch less beam.
Steve has a 74 CV16 with a well tuned newer 115 Merc and gets high 50's with his, but it a newer Merc with HP rated at the prop and he knows how to set up a boat, your motor would be HP rated at the power head, so you should easily get low to mid 50's if your motor is running and set up right.
Your boat looks to be "redone" with new seats and paint or gel. There should be a tag glassed in or metal plate with model and serial number some where in the boat, find the tag/plate and that would tell you year.
Report back with what you think of it ...