Does anyone know where I can buy a piece of this or what I need to seatch for on Google? I want to put a bigger piece because the trolling motor is destroying the paint. 

I believe you can buy it from Tracker

As mentioned above. That may well be the cheapest and easiest option for a small quantity. You might also try stewartsurestep online. 

is the prop the item scratching the paint. If so perhaps always turn it to the outside when you put away.

 Yes but it is already scratched so I would still like to cover it up. 

I bought a small piece from my Ranger dealer