I'm in the process of shotblasting and painting my Escort Cossie shell, now in the floor pan near the foot wells are lots of little slots like vents cut straight through the shell, this is a standard thing obviously but they covered with that semisolid about 3mm thick sticky sound deadening stuff if that's what it is, I'm assuming this will all need replacing in the same areas it's removed from otherwise waters going to piss into the car like no tomorrow.

So question is what exactly is this stuff and where do I get some?

Cheers