Yikes! You are missing the entire inner cowl. To fix it correctly, you are in for some serious work. You will need the full inner cowl panel.
The problem is, the ones sold by the vendors are not formed anywhere near correct at the bottom.
The good news is some of them sell a half panel(the bottom half) that IS formed correctly.
The bad news is that you need to buy both panels and graft them together. It is the easiest way to make the repair in my opinion. Trust me.
The full panels have a horrid gray primer, and the half panels are black EDP primer.
Carl


1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission