I would like to make a one piece mould (less work) of the front of my Elan so I can make a one piece flip front. The bonnet will be fitted and blended in prior to making the mould. I can't see any locks. The mould should flex around the wheel arch lips. Can anyone see any problems?

I drew a few lines into your pic, where I would add flanges. I did not consider any changes, that have to be done, to convert it to a flip front (filling of the bonnet recess, maybe adding a backward edge). As far as I see, this would be the minimum, and you still would need to add the bottom piece afterwards, as it is at 180° to some of your cut offs. And 180° hand formed without mould making in mind are likely somewhat between 175° and 185°.

Thanks for that.  Looking at the photo I reckon that I don't need to take the bonnet all the way down the back of the arch, stop around half way thereby removing the section that curves inwards and negating the requirement of the joint along  the wing. I can make the lower section separately, fixing it permanantly to the body. I want to build the splitter into the front in order to add stiffness. As this is a one off part I am quite prepared to, carefully, cut the mould to get it off if necessary :-) Any damage done to the carbon can be repaired. This probably sounds really bodgelike to experts, but with only 20% skill level you have to do what you are capable of. I guess the finished article will prove just how good or bad I am at this stuff.