Seriously, USE the scope. Unless you are a Gorilla and crank on the screws or worse, decide to twist it whilst attached, you WON'T mar it. It's not a museum piece, JUST USE IT!
I have been using Tak for ages now. I use the screw clamps. I have never once managed to scar up an EP or adaptor connection. You'd have to be a complete numby to do so. And don't go through life fretting about it - only the pedantic lillies worry about a mark on such things. I mean, it doesn't affect it's use, nor can you see it unless you take it out.
I have had more issues with compression rings than with screw clamps, especially Chinese compression rings (some just outright won't hold - the ones made for Stellarvue are a prime example)
JUST DO IT
