Ultrasonic cameo carving production

Hi, I am looking for a source to do small quantities of 2
color/layered agate cameos by ultrasonic production of a graphic
design. I have had 2 sources and lost them to hard drive failure.
New searches have not been fruitful. I have just learned of this
list from an old acquaintance. I would be grateful for referrals. I
anticipate a one time charge for the master die and a charge for
size change then per piece charge for the stones.
Thanks, Jay Cardwell