The small bonnet on my kit had a slightly different curve from the recess in the front clam that it sits in. Also I wasn't keen on the open gap around the small bonnet.
I moulded a gutter onto the front clam, around the edge of the bonnet opening. For the shape, I got glued some wood strips in place and moulded over them. The hardest part was getting the CSM to follow the shape of the wood strips - it doesn't happily sit down where it goes over a corner. After a couple of failed attempts I put a layer of tissue glass on first, then let that set, then put on layers of CSM. Even then it ended up a bit wavy in shape. No doubt there's a good solution but I'd have saved a problem by rounding the edges of the wood strips, so the glass didn't have a sharp corner to follow.
http://www.madabout-kitcars.com/foru...pictureid=1719
http://www.madabout-kitcars.com/foru...pictureid=1720
http://www.madabout-kitcars.com/foru...pictureid=1721
To straighten out the bonnet, I secured six M8 bolts to its underside, each welded to a metal plate glasses onto the bonnet, with four at the corners and the other two half way along the edges of the bonnet. These pass through the sill. Nuts sit above the sill and below it. That way I could adjust the level of the bonnet and so persuade it into the right shape. Sorry, no pics of these bits!