I have 1957 Mk 1 #S942330, a post-factory fire product that has the only Jag fender skirts of their particular design that I can find. They have what appear to be genuine, stamped-in numbers on the inside upper frame surfaces (as do my other, conventional cut-away skirts on my '56 #S940061). They have no raised 'bead' around the wheel cut-out. The cut out is what makes them so odd, to my eye. It is about half-way between a full spat and a regular cut-away skirt.
I have searched through hundreds and hundreds of photos of Jags and nothing like them is shown.
Does anybody know anything about these skirts?

Steve T.