I don't know if this will help; but there is a Haliotis pulcherrima
Gmelin, 1791 which goes about 2.5 cm and comes from eastern Polynesia.
That's about as close as I can come to your shell. Consult Abbott for a
picture: pg. (about) 20-21 in the compendium. Rice lists it as about
$8.00.
Art