Some finishing details...

[tetters]

Your skills are more than adequate for the task, the above photo shows that clearly.
You need a hull...could be a wood block cut to the shape of the hull.

The tug here has a squared off bow, and transom. Bending the above deck part ( Bulwarks ) may be touchy, but do-able.
The main deck enclosure is a basic rectangle, as is the pilot house,and a lot of the "maritime details" bitts, liferings, even windows and doors, are purchasable.
The Revell "Harbor Tug" kit hull is 8-3/4" long ( 63'-6" in HO ), and is the kit I modified to build this:
[ATTACHMENT NOT FOUND]
I cut the hull off at the waterline. The pilot house on this is scratch built with styrene sheet and strip.
If you were to do the same hull, cut at the waterline, glue in the deck, glue the hull and deck assembly to a thin sheet of styrene, (to lock the shape in), you could then do the bow and transom "surgery"/ rebuild, and scratch from there up.

If nothing else, just give it some thought. Where there is a will, there is a greedy relativ--- :oops: ---, a way!
Oh, the ladder, midships, attached to the side of the superstructure? That's a caboose ladder from an Athearn kit, re-formed as seen. There's one on the Starboard side also.

Thanks for the vote of confidence Sump. My comment was not meant to be taken as a poor attempt modesty. I'm pretty sure that I'll be able to pull this off.

( Gosh! Now I hope that doesn't sound arrogant?!? hock: )

Seriously though, the thing is I always approach there projects with some trepidation and humility. I do the best that I can but don't claim to be the best.

I do like and agree with your approach. Break it down into three basic shapes, Hull, Deck Enclosure, and Pilot House. I think the tricky part will be to get the scale right. Although I do have the Sylvan RR Tug Kit and can probably modify the hull to get the basic shape of the Iris G Hull down and then scratch build the rest from there.

Thanks again for your advice.