Your experience with the inner cowl panel is pretty what I (and most others who tackled that job) experienced. Mine needed some serious massaging like yours did.
But you got er done.
Get prepared for similar issues with the inner-to-outer cowl piece.
Thanks! And yes, there were fun times ahead!
Brian
'51 Chevy 3604 Project '28 Chevy LO basket case '83 GMC Sierra 4x4