Frame number location on a model A

[old car guy]

Has it ever been known why ford put the frame number where he did. There has to be a logical reason for the placement of the number where it was put. But why not a slot or a cut out where the cowl covered it for viewing. It just seems strange about the placement of the number almost like it was put there for a reason . I have always wondered about the placement and hope some one can enlighten me as for the real reason . Thanks