Revell 1/96 USS Constitution - which year?

You're correct that the big 1/96 Revell Constitution represents the ship somewhere around the 1812 timeframe.

The smaller 1/196 Revell kit represents the Constitution after it's 1929-30 restoration up until the current ongoing restoration which is attempting to take the actual ship back to it's 1812 configuration.

Mark

As I understand it, Mr. Campbell intended the plans he drew for the Smithsonian (on which the 1/96 Revell kit is based) to represent the ship's 1814 configuration.  He drew those plans a long time ago (in the late '50s, I think); a great deal of research about the ship has been done since, and if Mr. Campbell were making the drawings now I imagine he would change some things.  (Most conspicuously, perhaps, he'd probably omit the hinged gunport lids.) 

The old Revell 1/192 kit (well...come to think of it, they're both old now - and so am I) seems to have been intended to represent her has she looked at the time the kit was designed (it was originally released in 1956), with one big exception:  for some reason or other, somebody decided to give it the notorious Andrew Jackson figurehead.