It wouldn't have been as funny if I said---spent a bit of dough($$$$) for modeling clay at Toys R Us--------

Altho I agree that play dough doesn't hold its shape as well---------its the thickness that matters here and it works fine for that-------of course if you want to make a casting or something similar-----there is a 2 part sponge stuff that works great for port shapes etc-you can slice a thin cross layer of it at any spot, lay it out on scaled graph paper and count the squares for the port area at any spot--Its sponge and you can work it out of the port after removing the valve stem thru it----