I built a similar carbon fiber coaming lip last fall and and had the same situation with a recessed deck. The key is to maintain adequate clearnace under the lip to permit easy release of the sprayskirt shock cord. This is particularly key where you go across the "ridge" where the flat recess areas intersect the sloping side of the deck (pay special attention to the back area). Otherwise, use foam board insulation (Pink Owens-Corning has very small grain structure and forms easily) to create the horizontal lip "platform". Maintain a side-to-side level "platform" by cutting varying andgled wedges of foam to go from the sloping sides to the flat recessed areas.

I used a fairly good amount of 3" wide clear packing tape to hold and cover the foam and provide a smooth, easy to release surface. Cut into varying strips to work around the curves; the minute ridges left by the tape are easily sanded out.

Last pointers (learned the hard way):
1. Make sure you don't "trap" the layup with an underhanging lip of CF when you lay up. I added an inch of foam on the underside of the deck cut verically flush with the inside face of the coaming. Trim the excess, or assure it gathers towards the center before curing.
2. Pop the lip off the coaming within 24 hours. I let my set up for 3 days and the carbon fiber lip was so stiff and tight I almost killed myself or the boat (for a moment there I wasn't sure which was going to give first) prying it loose. The carbon fiber wasn't going to give.

It's worth the effort. the carbon fiber lip is great!