It sound to me that now is a good time to get an apprentice to do this sort of mundane work for you whilst you concentrate on having fun with your hand strapped down your trousers....in the future I can forsee armed conflicts arising about whether it should be strapped down the front of your leg, or down the side or even...lawks a mercy..... down the back........hush my mouth!
or you could...
Wrap the sandpaper around a 2" stick , at least that way if you oversand you won't get finger shaped depression in the blank, then you can use any of the other suggestions above. Good Luck with it