As you discovered these not much info on the internet
. You can expand your search to include other gulfstar
models to get a general idea for design, manufacturing, and performance.
In general gulfstars are considered to be spacious but not as high quality or performance as competing boats.
You can search this forum for Gulfstar and get a snapshot of opinions.
Of course, how a particular specimen was maintained makes a big difference so learn to know what the expensive repairs
, and saturated decks. If you know what engine
is used you can also search on that.
Good luck in your research