Just cut the stock covers with a little planning and drawing, to make sure they lined up and came out right. Practiced on the spocket cover a few months ago, which came out nice so now I have a matching set.
They do look good. But I am worried about road junk getting in and fouling the belts and rollers. Wont look so nice when it is grimey. Have you thought about sticking some thin perspex on the inside to keep it clean?
P.S. I just sprayed mine gloss black and they look better than that std. matt grey rubbish. But not as good as your vented covers. Nice work.
I'll try to snap a picture of the sprocket cover ASAP. As for junk getting inside the belt covers, I ran with out them for about 2 months and didn't seem to have ant effect at all. Although I didn't do much bad weather riding, maybe one or two rain rides.
I also thought about using some epoxy to hold in some kind of mesh(still thinking about it), but I'm alittle more worried the mesh coming unglued inside, than something actually getting inside. Also there is not alot of clearance inside those stock covers if something just slightly comes unglued could be a big problem.
As for building more, I may do it, if I can get a hold of some stock covers cheap and stock sprocket covers cheap. I would rather screw up a set I own than someone elses. I wouldn't want someone to have to wait forever, so i would have a back up.
As for doing it yourself, really not that difficult. Like Strati suggested in a earlier post a fine jig saw blade works good and then a drimel to tidy things up, then of course sanding to smoothe it all out. I used a plastic cutting bit, still tended to melt the plastic a bit but did a pretty good job. Oh, and some patience, take your time.
Thanks for all the compliments.