Good luck with this model, by the pictures you posted and your comments this is indeed a poor quality casting with even poorer details...the front grille alone is a quite clear indication of the problems with this resin body, it would be best to cut it out and scrachtbuild another one....or find a replacement from a model kit.
But I have seen in this forums real low quality resin/plastic kits that where turned in to scale model masterpieces(with a LOT of work of course) by several members here, so theres always hope!!
The real prototype car really looks interesting and impresive!!!
Again good luck and keep us posted on your progress.