It's tough, but I think I would probably bring it in. A fish that big is relatively close to the end of its lifespan, and has already spawned several times, so its genes are in the pool already. I'd get a skin mount of it after the certification process, because a fish like that is a fish of a lifetime and should be remembered.
The lg bass record in this state will never be broken! Even if someone grew one as a pet. This week the Tennessee state record bass was broken after 60 years. Even that fish wouldn't have been a Mass record.
I remember more stories of the people that release them than the people that keep them. Like this kid. http://www.onthewater.com/12-year-old-catches-and-releases-possible-state-record-bluegill/