I hadn't thought to check those measurements against mine!
Caveat: my body is from an old hot rod. Last licensed in '78, owner long past. I'm told it last ran a nailhead and was made into a rpu although it was originally a roadster. Supposedly came out of California in the '60's.
Firewall vertical: 22.5" to the top of the firewall bulge, 23" measuring the body flange where the firewall riveted. This is an eyeball measurement, the body is on the frame and channeled somewhat. I can try for better if desired.
Cowl horizontal length, cockpit lip to the outside forward edge of the firewall bulge (ignoring the radiator support bracket) 16" not 16 1/2". Firewall bulges out 1 1/4" beyond forward edge of the body flange.
Cockpit horizontal length: 38 7/16" not 37 1/2", door gaps look good at upper edge
Cockpit width at widest, outside to outside, 46 1/2" not 49"
??
Turtle deck width: 44" not 42"
Firewall width, outside of body flange to outside of body flange, 30 1/2" not 29"
Body length (had to pull a fender). I get 90" overall, not 90 1/2". Axle centerline is of no consequence.
More?
Sure hope that that drawing is inaccurate.
Mike