Hi,Rickles your model also comes out at 50 feet long. Don't forget your 'scale man' he is going to be about 3 1/2 inches high. This against a man of 5' 10" tall so a lady might be 3 1/4 inches tall, unless you favour high heels!
Locks allow for a 70 foot long boat, and narrow canals have locks which just take a single narrrow boat. The more used commercial canals Regents etc, have double width locks.
The visible 'bump' on the rudder is to stop the rudder from going back under the stern to hit the propeller.
The science of the locks was very clever and worth reading how they minimised the use of water.
I did at one time consider buying a canal boat but on reflection decided that hiring one was a better bet, especially as later my wife worked for the Waterways Association and we got a 50% reduction on hiring their boats.
regards Roy