Yes, I am a long-time modeler and am very familiar with both resin and etched brass/metal details.
In fact, I’ve built a number of resin ships for 28mm (closer to O scale) wargaming,
including adding plenty of extra detail (rigging, block and tackle, pin rails, etc.).
I had read about the “boxcar width” issue in one of your earlier posts and am already planning a number of modifications.
For one, I plan to remove the lift gates at both ends and replace them with a simple bollard and chain arrangement.
Second, I much prefer the look of the “Wittow”, with the deck house above and dead center of the tracks.
I’m planning on modifying the support structure to span the width of the ship so that there will be plenty of room between the supports.
And, depending on the stanchions (do they have holes for the thread?) I may replace the thread with brass wire just for durability sake.
What I hadn’t counted on was the dip in the deck issue that you mention.
While I need to see the kit before I decide,
I will probably add a real wooden deck on top of the existing deck which would allow me to rectify the problem,
and possibly even raise the top of the rails a bit more above the water allowing for a slightly higher dock and seawall.
I just received Bar Mills Raquette Lake Navigation Company car float apron which I think will match nicely with the smaller sized ferry.
Since I’m modeling a mid-depression era logging line (with occasional NYC traffic - because I already have a lot of NYC stuff),
that doesn’t have money for a new or larger car float (and I really enjoy switching).
I plan on the ferry making multiple runs across the river each day.