There is a source (Kansas) for good 1935-37 rocker panels still in business.
The good 1935-37 cowl, door, and cab corner patches are gone.
The good 1938-47 cowl, door, cab corner, and floor panels are gone.
"Basic" 1938-47 door inner and outer patches are available (Texas) not good, but can be a better value than flat sheetmetal.
The 1948-52 tall cab corner patch (not Carpenters) can provide a good base for the 1938-47, but will require the back notch to be hammered in and other moderate reworking. Again, not a great solution but a good value vs flat sheetmetal.