This is still a bit of a work in progress but it is now 90% done. Just another modification and I will be happy with it.
The numbers on the part should help in adding the little flange to the part so the cover sticks out over the chain mid way along the swing arm. The chain is pretty much covered by the swing arm here anyway but adding the flange will make it a bit more so. Once this is done the only bit of the chain exposed will be from the lower jockey wheel to the chain tube. I am still thinking about how to cover this but its a bit difficult to do if you leave the rear wheel well open at the bottom so its easy to change the rear wheel. If we were using a 26" rear wheel the derailleur would be much higher off the ground and this would be simplier to do.