That picture of the 51 ton, are those the same type as the USRC Alabama and the USRC Louisiana that captured the pirate ship, Bravo off Florida in 1819.
Yes it is. I used Chapell's book as a reference. A number were built, exactly how many is a tad confusing (due to his writing style). A Coast Guard history site also has a great drawing labeled for the Louisiana.
Redondo, Don't tell us that that next one with the rivets is in SB Scale
CraigH