Look here for the HIN actually stamped into the hull or a small riveted plate:
Should be a 12digit #
Does it look like there was a plate at some point and it's now missing
Spend some time really looking, some have found the HIN buried under layers of paint.
If it's missing, then it's likely pre 1974. You don't have the title or registration paperwork? It should list the year, if you don't have it, does the state where you live require either?
Look thru the Starcraft brochure pages at the top of the SC forum homepage. Most Starcrafts came in a single color per model year, and the colors weren't repeated the next year.
How long is your SS? Based on what I can tell in the fuzzy pix, it's likely a 16ft since it's not rated for above 90hp. If it was, it'd likely be an 18ft'r....