I can't see in any of the pictures: What is your support under the sponsons? Seems like they wouldn't stand up with just decking as the structure. I would have thought a bit of cylinder extended downwards would do, but even just some structural stuff would work.
Or, chains from above. Still, that's mighty thick decking. I'd not complain as is.
I will say some addition to the tail boom might not be amiss. Perhaps some edge and cross strips with rivet heads, suggesting an iron framework, visually tying the whole thing together.
Maybe even a small walkway on top, or is that too much?
Must say, had some doubts at the start, but it keeps impressing me at each stage.
Beautiful as is, better when painted.
Well done!
Doug