These Japanese made A5's were selling from $800-$1200 this past year.
Best bet is to have it examined by a good gunsmith.
I don't think there is an invector plus model. Invector Plus is the choke system Browning uses on newer shotguns.
The Invector Plus choke tubes were first introduced in the 1989 Browning Catalog which was published in October 1988. Keep in mind that the Invector was already standard on most shotguns and the Invector Plus was slowing being made available to many models. The Invector Plus choke tube system was available first on BT-99 models and then the BPS and high grade doubles.
Either Invector or Invector+ depending on how it left the factory.
Browning did not make an Invector model. That is the type choke system of the shotgun.
Browning's web site has the current information.
You will have to call Browning to find out.
What is the question?
10-20 usd
Go to Browning.com and type "Invector Choke" in the search function.
Made in 1996
To change the choke of the shot