I reckon once you've done the ballasting and added a few weeds here and there you'll have got the balance about right.
"Heybridge Basin" hasn't shown up any ghastly problems likely to lead to untimely abandonment, and I want to take it through to a reasonable state of completion. If so it will be my third half-decent layout out of my 18 so far and it can sit in with my H0 and H0e layouts which are both much smaller. Ballast and weeds will make a big difference, and then I can think about smaller things like the lever frame and an oil lamp.
But first! It is difficult to show an overall balance here, but the whole model does look a lot better if I add an extra 400 mm to the left.
I can use Module B from my first fiddle yard to do this.
This gives me space to include a level crossing with road access to the yard, and one or two more trees along the way to the fiddle yard. I could even have a large shed to block the view - there were two for the timber traffic here and something similar for the railway traffic would be logical.
Adding Module B gives me four possible layouts with three different overall lengths, all able to do much the same thing but with an extra wagon if I use the extension for the sea lock. If I am careful, Module B will still be able to fulfill most of its original role as a headshunt in the fiddle yard project too.
Of course, if I had made my sample track 20 mm longer this could be up and running in an hour, but I made the track for a display case and then decided the display looked much better without it . . .