Seat diaphram mounting

[Scott.Mackay@intl.sematech.org]

     Hi all, 
     
     Just received my new seat diaphrams from TRF.  Went to install them 
     this weekend on the '76 '6 and came across an interesting problem.  
     The old diaphrams were crossed webbing, which I knew.  What I didn't 
     know is that they have only four mount locations on the long side.  
     Thing is, the new ones only have THREE mount locations.  
     
     Any ideas how to drill new holes without dissembling the seat bottom?  
     
     Scott Mackay
     Austin, TX