From To the Sound of Guns and other sources.
There are also two 6.4-inch Brooke Rifles from the CSS Atlanta at Willard Park in Washington Navy Yard.
#1610 was on the starboard side and #1587 was the port side gun.
Trunnion marks "J.R.A. & Co. // T.F. and 1862"
J.R.A. stood for Joseph Reid Anderson, owner of T.F. (Tredegar Foundry).