MK X 4 Speed Question

Heres an unusual question for those of you that may know.
What type of material did Jaguar originally use for the transmission top cover when using a 4 speed with OD?
I was recently sent one, and it is made of leather.
Can this be right or did someone get real creative and decide this would be easier to fabricate?
Jaguar was a bit strange for using Plastic top covers in early E Types, and eventually changed them to metal.
Perhaps the small numbers of Manual transmission MK Xs didnt warrant a better material? MK Xs were not originally slated to use manual transmissions, and perhaps this was a quick and cheap cost effective solution to help facilitate the option.
I dont know if I even want to use this thing just from a weatherproofing point of view.

Mk2s used a fibreglass type of cover, which was then covered by the console, ditto, I think, for E Types. I would expect the same for Mk10, certainly not leather.

Hi,

Fiberglass and steel used on E-types , always steel on XJ S1-S3 (at least all I have ever seen).

The gearbox top plate/cover with the strikers for the gears is always an alloy casting IMO. (Some type of aluminum or aluminium.)

Cheers!

It’s not the top of the gearbox I’m referring to. It’s the cover over the top of the gearbox tunnel. On a manual 4speed with overdrive.