Vintage Donkey Silver high quality Abalone Brooch Pin in sterling silver

Vintage Donkey Abalone Pin/Brooch
1.2”
Good condition for age
Abalone in tact
Silver has some scratches
Pin closure works

On hind leg:
Stamped with “PVI” high quality in what I would describe as a sun burst
Stamped with “ST”

On ear:
There is another stamp I can make out a “3” with 4 lines under the three and all are in a circle

Please review pictures in details before purchasing