I did some digging about the Harriet Lane a few years ago, when I was working on a series of line drawings of ships of the Coast Guard and its predecessor institutions for the Coast Guard Historian's Office. That was quite a while ago, but I am not aware of any information about her that's turned up since.
The first thing anybody learns when researching nineteenth-century American revenue cutters is that the records are horribly inadequate. The old U.S. Revenue Cutter Service did a wretched job of record-keeping - at least where its ships were concerned. Back in the 1930s, as part of a New Deal WPA program, some anonymous researchers dug through what they could find in the National Archives and the records at Coast Guard Headquarters, in an effort to write a definitive history of all the ships that had served in the CG and its predecessor organizations. The outcome of that project was a fat, typewritten book called the "Record of Movements," which is the nearest thing that exists to a primary documentary source on the history of American revenue cutters. It's an infuriating volume. It's organized by ship name; one ship gets ten pages of documents, while another gets less than a page. It's entirely possible that some revenue cutters aren't in that book at all - i.e., that the U.S. government has officially forgotten that they existed.
I'll try to remember to dig out the "Record of Movements" and refresh my memory regarding what it says about the Harriet Lane. My recollection is - not much. Here's what I do know about her. It won't take long.
James Buchanan, fifteenth president of the U.S., was a bachelor. His niece, Harriet Lane, served as hostess at White House parties during his administration. Somebody invented the term "First Lady" to describe her position, and apparently somebody in the Treasury Department thought it would be a good idea to name a revenue cutter after her.
A few years earlier the Treasury Department had been through a bruising scandal, when it built several extremely unsuccessful revenue cutters based on the concept of the "Hunter Wheel." (We took that one up a few weeks ago here in the Forum. The Hunter Wheel was a crazy idea involving paddlewheels set on vertical shafts below the ship's waterline.) The Hunter Wheel was such a flop that Congress revoked the Treasury Department's authority to build ships for several years. The Harriet Lane marked the Department's return to shipbuilding. Somebody had the good sense this time to hire William H. Webb, one of the most brilliant designers of clipper ships, packet ships, and various other vessel types, to design and build her.
There's a decent, but basic, set of plans for the Harriet Lane in Webb's Plans of Wooden Ships. Those plans, I'm reasonably certain, were the basis for the ones in the Model Shipways kit. Sometime in the mid-twentieth century, the Smithsonian Institution commissioned Merritt Edson to draw a more detailed set, with enough additional details to allow the construction of a detailed model. (I don't know whether the Smithsonian ever actually commissioned such a model or not; if so, I haven't seen it.)
I am aware of two other contemporary images of the Harriet Lane. There's a photo of Britain's Prince Albert coming ashore for a visit to New York sometime before the Civil War. The contemporary caption indicates that one of the ships in the background of the photo is the Harriet Lane. The background of the photo is out of focus, and there apparently was a good deal of mist on New York harbor that day; the Harriet Lane shows up as a vague, dark grey smear, a fraction of an inch long. Then there's a pencil sketch by a war artist for Century Magazine, showing the capture of the Harriet Lane by Confederate forces at Galveston. It was published in The American Heritage Century Collection of Civil War Art. The artist was mainly interested in the human figures in the scene; it shows scarcely anything of the ship. I'm not at all certain he ever actually saw her; the drawing probably was done after the fact.
To my knowledge, the small-scale plan in the Webb book, the useless photo, and the useless pencil sketch are the only contemporary visual depictions of the Harriet Lane. If you do much research in U.S. Coast Guard sources you quickly cease to be surprised by such things.
None of those materials gives even the slightest hint about the ship's color scheme. I have no idea why Pyro molded the hull in green. (Actually I've never seen one of those kits in its original box - with the name Harriet Lane on it. By the time I first bought it, it was being called a "Civil War Blockade Runner." Maybe the initial release had a black hull - which would make more sense. The instructions in the Model Shipways kit, from which the Pyro one was pirated, called for a black hull.) A few months ago the CG Historian's Office hired me to do a revised version of my earlier line drawing of her, this time in color. The CG Historian, Dr. Bob Browning, and I talked it over at some length. On the basis of photos of other revenue cutters of the period, we concluded she probably had a black hull, white superstructure, white paddle boxes, copper-sheathed hull, white lower masts, black yards, unpainted upper masts, white gaff and boom, white bowsprit, varnished wood deck furniture, and white boats. But that's just a more-or-less educated guess.
When it comes to the Susqehanna, I'll have to yield to somebody else. The Navy Department's records are better than those of the Coast Guard, but information on Civil War warships tends to be extremely variable.
LATER ADDENDUM: I looked up the Harriet Lane in the "Record of Movements." She gets three pages, most of which consist of quotations from orders and other official documents. They do no more than establish where she was ordered to go on particular dates. There's nothing in them about the ship's appearance. The coverage of her in that volume stops in 1861, when she was officially transferred from the Treasury Department to the Navy.