Nice photos, Terry C. It looks like a very interesting place; it's now on our list. The cannon in the third photo, with it's below-center trunnions, equator ring around the cascable, the rectangular vent field and the Royal Cipher just this side of the trunnions, looks like a probable British Navy gun to us. With their presence is this area throughout the 1700s, it's not inconceivable.
DD, that wooden barbette carriage in your second photo was dismantled and lying on the grass near the entrance to the 8" shell magazine the last time we were there in December of 2005. It was very educational to see exactly how all the rails and transoms fit together! A unique opportunity. It is interesting too, that not 20 feet from where your wife stood in 1989, was the spot where a 15" Dahlgren shell from the Monitor, Nahant penetrated 18 feet of the sand and marsh grass rampart during a Federal bombardment in 1863. Also during one of the seven, extensive Federal Navy bombardments, not one man was lost, but the fort's mascot, a cat, perished. The exhausted, grimly, gaunt-looking artillerymen had only one request of their commander which was, "Sir, would you kindly mention the loss of our cat in your official dispatch to headquarters?" He did.
Tracy and Mike