You are right about the pearl - silver South Seas with a definite blue cast. My guess is that the pearl is from Indonesia or that general area, as I have acquired a number of other similarly-colored pearls from that region. As I recall, the unset pearl measurement was roughly 16mx20mm.
I'm so glad Big Papa went to a loving home!
As an aside, if anyone visits Pinterest, I have a gallery devoted exclusively to pearl creatures, hundreds of photos, mostly antiques, but also some modern ones. A good source of inspiration. I would love to own them all! At least there is some satisfaction in collecting photos. You can find the gallery under Sheri Jurnecka.
I found a brassy chain to wear until I figure out a more permanent solution for him. I am thinking of BBA or some white keshi, but he is a little heavy so I want something that will support him well enough, but also look good with him!