Really good fiberglass has 2-4 times the tolerance spread of poor steel. Plus warp, waviness and variation as it cures. Look closely at a 67 or 68 Shelby fit of the hood. They spent hours getting the production ones even reasonably close.
My '64 1/2 vert. Ordered May '64. D code 4 speed, handling package, caspian blue, accent group, Ford blue manual top.
'68 vert. driver. Owned since '77. C code AT, AC, PS, P disc B, PT lime gold, standard black interior and top. NOS RF fender and left quarter.New top and folding glass.