Tank Pad (1985/86 WR/WRX)

On the 1985/86 (probably other years too) there's a foam/rubber pad (2 of them actually) between the tank and the frame.
This basically looks to be the kind of self-adhering foam that I could pick up at a well stocked hardware store. Is that what most people do, or is there more to it than that?

They are rubber not foam. They are not strictly necessary in my experience on plastic tank bikes. The front bolt mount holds the tank on and the seat holds it down. For some reason I could not get my 84 or 86 tanks to sit right with both rubber pads in use. I ditched the one closest to the seat and the tank positioned fine. Never had any issues in many years of racing these bikes.