Hello Robert,
I am excited to see the progress on your build of the Revell USS Constitution!
With regard to the stern decorations and the appearance of the transom during the War of 1812, no one knows exactly what the stern looked like at the time, as there was no photography available, and the details present in contemporary paintings is somewhat conflicting regarding many details, such aas the colors of the decorations, and even the number of windows present. There are many threads in this forum that deal with this question.
The Revell 1/96 model's stern is based on the 1/48 scale model of the Constitution in the Smithsonian Institution, based on plans created by George Campbell, who in turn based those on the famous "Hull Model" built by crewmen and presented to Captain Isaac Hull after his victory over the HMS Guerriere.
A few things are certain. One, at the start of the War of 1812, the spar deck had no gunports on the stern. On the gun deck there were stern windows that may or may not have doubled as gunports, but contemporary paintings show 5 or 6 actual windows. During the "great chase"early in the war, before Old Ironsides was involved in any battles, in which USS Constitution escaped 5 British warships in light winds through superior seamanship, Captain Hull had his carpenters cut holes in the stern at the spar deck in order to bring some stern chasers to bear on the pursuing ships. These ports may or may not have been covered back up during subsequent repairs. It is not known if they existed during the battle with the Guerriere, but significantly, the Hull model, which is by and large regarded as the best primary resource for the ship's appearance, does not include any spar deck stern ports, and it was built by the crew after the battle.
In general I think the Revell 1/96 stern is a good representation of the stern as it appeared at the start of the War of 1812, and the smaller Revell 1/196 stern represents a post 1830's overhaul stern, which is close to how the stern appears today.
Cheers!
Jose
Jose Gonzales
San Diego, CA