Not trying to take anything at all away from your vid Rob, but I did a thread on flame polishing awhile back
http://aussiepinball.com/index.php?topic=1568.0
and need to mention, for those that are considering doing this, you absolutely must clean the ball track out of the ramp before polishing. It needs to be spotless, no dirt at all, just your sanding marks, otherwise you will bake all of the dirt into your ramp and will not be able to get it out again, it melts down into the plastic.
Just a bit of info to prevent people wrecking good ramps.
Good vid tho, shows how quick it all happens, even quicker with a big torch