I installed the hinges and bent the doors on the upper cowl using brute force plus a roller and achieved fairly good fit as long as straps were used. I tried using the roller only and also the manual bending, but superior results were achieved using both rather than either method alone. The manual says a good fit requires all other nutplates to be in place prior to fastening down the doors, so I alodined the metal to be riveted and placed the rivets. I started on the firewall nutplates of the upper cowl, and will nutplate the lower cowl and nosebowl next