Seems like there were no variations through the production year at San Jose. All were what we refer to as the speckled style with the brown jute backing. Remember there was a fold down and non fold down version.
Since you have a Mach I it would have had the full underlayment under the mat and areas where there was no mat on the passenger side - different from the sportroof underlayment. In addition you had the drivers side cardboard trunk drop panel (forgot the formal term for it at the moment
and the trunk board over the gas tank on the drivers side.
Of course there is a long discussion on the underlayment for 69 Mach I and Shelbys as well as not to make the stuff also on the site.
Original example from a car with a VIN approx 3,000 units from your cars likely VIN so it could have been built on the same day or close to.
Examples from a slightly later sample range
Some of these are included in the threads in the 69 Unrestored Picture Thread section of the site
Close up of the back side jute portion