Looks like it might be very loosely based on the Alexandra towing tug.
https://www.shipsnostalgia.com/media/steam-tug-alfred.469932/
There are a lot of model tugs named Alfred, of various vintages and sizes but none seem to match yours.
It is possible that the builder bought a GRP hull and then invented his own superstructure and above deck layout.
It is clearly a very old fashioned design with the exposed bridge so probably depicted as early 20th Century.
Colin