Fast231, I've got an Eastern Performance F/M, and had the same problem. I cut 2 vertical slits in the shroud, and ran 2 metal straps around the bottle. (The hose clamps on the bottle keep 'em from sliding off) With mine, the bottle isn't straight up and down, but it sits kinda low, so it's no big deal to me.
I work for the cable company and got the stainless strips from them. Guess that you could use 2-3 thick tie wraps, if you can't find straps anywhere.
SalvageV6 made a nice bracket for his, I believe the post is in here somewhere. He had pictures...