Tom, as you're probably aware, the GB's are open to all skill levels, and I can't see anything to be concerned about in your models mate! You wouldn't be 'mucking up' anything, as part of the GB idea is to help and encourage each other; if you make a mistake, or mess up some part of the process, there'll be advice on how to correct it etc. I believe taking part will increase skills, abilities and, more importantly, confidence, due to building alongside others of a similar level, and it also provided a bacxkground to each subject for everyone to learn from and enjoy.
See you in this, or the next GB then?!!