WWII fenders were usually made out of scrap rope, old rope that was no longer good for tying things up but was too solid to just throw away. Think of the rope fenders and bow mats that are stereotypical of tug boats
You can easily make WWII type fenders by taking a piece of plastic sprue of the right length and diameter, rounding off both ends, and then taking some jute coloured string or thick thread and wrapping it around and around the sprue until it's completely covered with no plastic showing, only 'rope'.
Make a loop of thread or wire at the top to attach the lanyard that suspends it.
