you dont want to make a whole body outta putty, it will be too heavy...........also, it might crack if you hit something hard enuff
i chop and shave sections i wont need and then fill with putty to get the shape i want. get some fine sandpaper and maybe a small file set....for the fine details.........
if you have a dremmel, all the better
this is how i made the nuvolari, but you might wanna check this tomorrow or sumthin, ive exceeded my bandwith
http://lefftoe.tripod.com/nuvo/