for future reference if you want proper carbon, you can buy flat sheet and warm it up and it effectively softens the resin, I have made several mounts for various items in a rally car this way, fuel tank gauge and big trip computer mount for the passenger side door when dave wood was alive who was beechdale saab/Subaru driver from notts, not sure if youd get a half round from it though as it does often cause bubbles in the resin if you over cook it, but the fuel guage mount and trip computer were 90 degree angles over the edge of a masked off desk then a little araldite reinforcement on the inside of the bend
probably a better way... its easy enough to make pieces with sheet and resin also, you just need a fishing pole repair kit for approx. 35-40 and you can make some really nice pieces up with a bit of practice, you'd probably get 4 12" half round that you could then bond on id think from one kit