Hmmm, been a LOOOONG time since I looked at it. If I recall, it would be equivalent of a heavy destroyer...in SFB terms...at least perhaps. It is a Constellation class starship. The four engine design was suppose to aid it in it's warp capabilities, but it came with a severe side effect...which, if I remember correctly, caused warp instabilities which in turn caused burnout of the warp engines to occur on a quick and regular basis. It is hypothesized that it was made around the time of the Constitution refit, or perhaps a little later during the time when the Excelsiors were king.
Now because of the constant break down due to the warp problems which were the side effect of the four engine design, it was not actually a long life ship, hence it was not as long lasting as say the miranda or excelsior, however, there are still a few around, but excessively outdated.
Riker commanded one in some wargames vs. Picard, and did some surprising things with his team on a ship (the hathaway I believe) which was outgunned and far less able than the Enterprise under Picard's command.
The Stargazer itself was retrieved at a later date. It was originally brought down under (once again, if I remember correctly) Picard, who managed to save most of the crew I think. He re-encountered it later as Captain of the Enterprise.
Just a few items on the Constellation Class vessel.