OOoh, lucky you! What's the worst that could happen? You know it won't happen, but even if you don't like it you can take it out and try again. You said you have practiced..take the top you like the least (haha, I bet they are all gorgeous) and start with that. I always seem to scare myself before new steps too, and only rarely have been really disappointed with the finish...at the least you will have learned. Go for it!