Hi Mundo
That's the only picture of Croxley Mills I've been able find online, I'm afraid, although it did enable me to create this view:
Click the image to zoom in
This is a 1920s plan of the complex. The track rule I'm using does have a tight minimum radius, but I can't get anywhere near fully reproducing this trackwork. I have noticed that there's a track right alongside the canal, which would have been immediately to the right of where the flickr picture would have been taken. I hadn't given it too much thought before, but I think I'll have to do a better job in this area.
If anyone wants to have a guess at what the arrowed feature might be then please feel free! I think it may be a disused gravel pit - although these are generally marked on the maps I've got - but why would there be two completely separate rail lines running around it?
John (partyspiritz) has come up with some interesting information already (if I may paraphrase). The boats in the picture are called Big Rickys and were built by W.H. Walker and Bros., narrow boat builders based in Rickmansworth between 1905 and 1964. The area where the Walker Bros. yard was is inside the scope of my landscape, as it were, but I'd never realised it existed. I shall therefore shortly be trying to create a narrow-boat-builders yard which should be interesting!
I'm generally quite happy to slot default assets together to make up buildings, but anything dock-related would certainly be of interest.

Having said that, the structure in the centre of your screenshot has 'St Albans Abbey station canopy' written all over it!

Ooh, just thought. What's really missing in RW is a set of open and closed lock gates. I'm using parts of Chaddock's bridge kit, but at 30m long they're a shade over scale for the purpose in hand!
This will show what I mean (and also includes my stationary travelling crane, which I think is rather natty!

)
Click the image to zoom in
Cheers
Bob