Re: 1973 Starcraft
CMW,
If your boat was produced after 73, it should have a HIN, which would show up on both the boat plate located near the controls and also on a thin strip of metal on the port stern right up near the top. If it was produced prior to 73 it would just be on the id plate near the controls. If it's 18' then its a cheiftain. Doesn't reall matter whether it is a 60's or a 70's era Cheiftain. They were all almost identical with the exceptions being as barato said earlier, the windhhields were different until the mid 60's, and the insides were outfitted differently from year to year and as newer materials/gizmos were available.
we have absolutely no faith in trying to id 60's era and up to mid 70's according to hin because MOST of the time the numbers meant nothing.
The best way to id an old LARGE hull Starcraft is to look at the stern (deepV, modifiedv, semiv,etc), look at paint scheme (green top/white hulletc.) and interior layout/color.
If you have better exterior pics and possibly some interior pics from before you started the restore I can probably tell you exactly what year it is.