Don't worry about it too much.
I always get a chuckle when folks worry about little scratches and the like, because just before you get ready to paint the entire aircraft it is scratched up with scotchbrite and sandpaper.
Same with the oils from your hand, don't sweat it - pun intended. Just clean it off with acetone or MEK - it won't hurt the aluminum any. I find that acetone is better as MEK can leave a bit of residue.
The bigger thing - try to keep it in a place with lower humidity if at all possible and of course out of the elements and the VS that you committd blood, sweat and tears to will be just fine.
Happy Building,
Rob