Ill post some pictures I still have to collect them. But what happens after the certification process.
What after... you would have to contact a few auction houses and see what they say. Auctions of loose pearls are not unknown off, just not very usual.
In fact, I would start with this, mentioning in the emails that you will have the pearls certified if they recommend this. Like this you have a chance to find out which of the pearls would be suitable for auction, if some may be best presented as lots etc.
I could be wrong, but my impression is that natural pearls only have a chance with the better international jewelry auctions. Which leaves you a dozen auctioneers to talk with. See
THIS LIST at GIA for starters. As natural pearls are best found these days through antique jewelry sellers, I'd guess there may be some interest in natural pearls from there too; try
THIS directory for British ones, and
THIS for US. These are not comprehensive lists.
Couldn't hurt to try, that's for sure.
Best of luck!
Hope to see the pictures here too...