Harriet Lane is an old favorite of mine, too-- one that I've given some amount of thought to as a potential RC subject. I'm a plankowner (1984) from the new USCG Cutter Harriet Lane, homeported in Portsmouth, Virginia.
I've done some research, but the one thing I haven't found much about is how the ship was handled at sea. Did they use the sails and paddles at the same time?
It seems to me that under sail alone, the paddles would make an awful lot of drag. And while they are fine in coastal waters and harbors, I would think paddles would be really inefficient if the ship was rolling in a seaway.....
All things considered, it seems to me the ship was likely a motor sailer most of the time.
I haven't found anything to indicate that the ship had independent control of the paddles--so I assume they both only ran at the same rpm in the same direction.