I see, that explains it. Thanks for letting me know.
You know, I actually tried and cut a spare one to the size, saw it by hand and couldn't get a straight line. Used the sawing machine and,...well what a mess. I ended up with a smaller frankenstein version of the original. I knew I wasn't talented with the needle...and I created a monster.
I am not looking for any particular vinyl material, just whatever fits nicely, that is semi-transparent and protects from dust (not even water protection is necessary)
...sounds like a plastic bag would do the trick

, but I am looking for something more shaped up like a keyboard cover.