Lee,
I had posted a response to your post and have since found the reference I mentioned. I knew it was an obscure reference so I went back through everything I had read on Requa guns. The reference I mentioned was in an article published in the May, 1999 issue of America's Civil War magazine. The article's author was Joseph Blough. In the last paragraph of the article Blough writes" In addition to being used in the sieges of Fort Wagner and Port Hudson, a single Requa battery later saw service at the Battle of Chickamauga in September, 1863. No other battlefield use of the unique, if short lived, weapon was ever recorded...etc. etc. " I myself have never found any reference, other than this, indicating use of the Requa at Chickamauga. This was the reason for my original post. A friend and I are going to attempt the construction of a Requa gun in his shop. If we are successful we would like to use the piece in reenactments.

Len