You said:
"Hi Gene: how about the 50c dice/aces mould on the Vegas chip site listed the date of the chip as 1968"

It does not matter what a chip site says. It is wrong.
Let me say this one more time.
The dice card mould that was used to make the dice card chips was made in late 1971 or early 1972 per Bud Jones. It is impossible for dice card chips to be on any table anywhere in 1968.
The person that owns the mould today also has the old Burt Company records. Burt Co made every dice card chip in the world up until the time they went out of business about 1988. Their records say the 1st dice card chip with a printed center (meaning a chip with an Inlay) like the Slipper chips was made in late 1972. That means 1972 NOT 1968 as you keep insisting.
The old manufactures records are the History of our chips.
I am done!!!!!