Hey Grimreaper... I have Never seen "quarter" (1/4) inch Masonite, only 1/8 th !!! Your photos do look like Masonite... let me see a "Edge" photo of the one you show with a close-up and your tape measure over it... please... the one I show is what came in a 65 Barracuda Formula S.... With the fold down Flap in those Barracudas, they had to be Thin... especially with the 14 inch wide Formula S wheels....