Mellotronists

Good Morning all - I'm in the process of demagging the heads on 1407 and 
am following Ken Leonard's procedure as detailed on his web site.  If 
you end up bumping one of the heads with the end of the demagger (wand 
type), do you simply repeat the process for that head?  If your thumb 
slips off the demagger's spring loaded switch while inches away from the 
headblock, is it safe to assume that you need to start the whole 
procedure over again?

Thanks (I don't want to erase any tapes),

john barrick (saving pennies for my M4000)