What gauge and grade is it?
I don't think there is an invector plus model. Invector Plus is the choke system Browning uses on newer shotguns.
Browning did not make an Invector model. That is the type choke system of the shotgun.
Invector is a brand not a choke. Invector is a brand not a choke.
A 12 gauge shotgun with changeable choke tubes that fires 3.5" shells.
Browning made choke tubes.
Go to Browning.com and type "Invector Choke" in the search function.
The Invector, or "Standard Invector" system" was introduced in 1983. A few years later, the Invector-Plus chokes were introduced to fit the new back-bored shotgun barrels. These two choke systems will not interchange. If you have screw-in chokes in your shotgun barrel, the kind of system you have will be stamped on the barrel near the receiver. You must use the proper choke system for your shotgun.
Possible, but, not recommended.
You will have to call Browning to find out.
Either Invector or Invector+ depending on how it left the factory.
To change the choke of the shot
Invector was Brownings original choke tubes that came out in 1983. Invector Plus came along later for the back bored barrel shotguns. They are not interchangeable. Invector Plus= late model shotgun, Invector = earlier design shotgun. Both are still available for purchase.