Grant,
I use a dew shield with a built in dew strap on my C11. I can’t remember where I got it from, but looking online it seems they cost in the region of £100 now!
No idea about the dual mounting for such big [heavy] scopes, but clearly can be done:
http://www.mikesastro.com/equipment/lx200r/C11vsLX200R.html
James