Thanks guys. The putty is Eurosoft Glazing for autobodies. Its some pretty good stuff. Its a bit messy as you can see from the dabs that I lumped on but it sands quite well. But it works out in the end as most of the front bumper is styrene sheet.
Still deciding what I want to do with the rest of the bodykit. I don't really want to make it a widebody but if that's the only way to hide the bowing of the body, then that's the route I'll have to take... ahhh... the joys of online auctions...
a.