Omega! Looking good, shipmate! Seems you had no problem with the stern planking coming apart on you - well done! Here's 2 cents in case the issue is on your mind - final bulwark height.
@DocTom and I have been talking about this issue as it impacts how the guns sit in their ports when the time comes. More important for you because of your motorized working wheels.
As you may have remarked by visitng other logs - there is a persistent problem of the caprail pressing on the top of the gun barrels and having to sand the bottoms of the carriages practically flat to ameliorate the problem enough so that the best outcome is the cap rail presses on the top of the barrel. The measurment in the pic below show why this happens. True story - I thought it was just because I did it wrong. Happens to me all of the time.
As you know I discovered the problem very late in my build. There were three parts to the problem in my case. 1) I planked the deck with 1/16" thick planks instead of using the precut, pre-marked, unscribed 1/32" deck from the kit. My decision took away 1/32" from the as built distance between the deck and the top of the finished bulwark. 2) As built, my bulwark was 3/8" high. At this point I put my guns on deck and noticed the massive shortness of the bulwarks

. 3) Then I went to the plans and measured the designed height of the bulwarks 9/16". That missing 3/16" was the problem! in my case add 1/32" to the problem because I used 1/16" thick stock to plank the deck.
I say all of this as a reminder to beware


You're doing a lot of cool modifications and increasing the level of detail on your
Harriet Lane and you may want to make sure you have the bulwark height necessary to accommodate her guns properly. Given the work you've already done on the sponsons, you'll need to keep the height problem constantly in mind as you plank the hull. In my case, I didn't need to do anything drastic to the sponsons when I heightend the bulwarks. In your case you're looking at making sure the axel placement is correct for your motorized wheels.
Even though it worked out for me, it was still wrong - I only added 1/8 to the bulwarks and the caprail is still a little to close to the tops of my guns by about 1/32" - 1/16" The yellow line above the muzzel should be longer


Blessings. Peace. Gratitude.
Chuck