Any-haps were do I go from here? Obviously this is what it looks like it is - as you so eloquently stated. Wealth to me is holding valuable rare objects of beauty (my wife has a differing view LOL). But even so if kept such things must be valued and insured and when push comes to shove sometimes treasures must be sold.
If a GIA cert is not the next move what is? Or do I just lock this away? What if it must be sold?
A GIA certificate doesn't list value. They allude to specific scientific points which are consistent with other baseline data only.
It is then where appraisers examine the data and affix monetary value, which is yet another layer of subjectivity, even when deemed genuine.
Most experts in pearls will say the same thing... it's in the eye of the beholder. You might think one thing, but your underwriter might think something else. You seem to have a good understanding of this already, as your issues are mirrored with mine in many ways. Once a pearl is drilled or otherwise fashioned into something, the value changes. In your case, unless the pearl is mounted into something extraordinary, the chances of it being devalued are higher, afterall much of the scientific value and pristine condition will be lost. As you have alluded, therein lies the conundrum.
When appraising naturals, one must consider all points, both positive and negative. Melo melo is not uncommon, non-nacreous and larger specimens have been described. One side has a considerable ridge of terminal growth overlapping the previous layers. Each of these points will halve the value, which becomes exponential. For the sake of discussion (only) let us compare it with La Perigrina, afterall they are simillar in size and shape. Despite what Christies auction house sold Elizabeth Taylor's collection for, we are only discussing the pearl itself. It was purchased by Richard Burton for $35,000 in the mid 70's. Unfortunately, natural pearls are not in great demand and if anything, prices per carat are generally lower. Factor in retail exchange, 17-20 is more realistic. Now, subtract non-nacreous 9-10, commonality 4-5 and inclusions 2-3.
I, like other natural pearl collectors are very wary to appraise value, but if I was to see this pearl listed and sold for $2-3000, I would not be outraged or suprised. I'm sure a decent underwriter would not have any issue with this and would insure it for upwards of $4-5000 of the replacement value. Of course they could never truely replace something as unique as this, but at the very least you'd probably be able to find something similar for that amount, plus a little for your efforts. You would likely need to deliver the pearl for their inspection. Before doing so, I'd suggest an array of professional quality macro shots over basic white including reference to size in millimeters. Explain to them, the cost of certification is not necessarily practical because of it's inherent properties and current market value.
BTW, check out this link of a previous post, where I posted images of candled natural pearls.
Candled Natural Pearls
Basically, all you need to do is make a simple box. Drill a hole in it. Not too big, not too small, just large enough to set the pearl in and allow enough light to pass. Put a bright LED or other light inside the box, place the pearl on the hole and use macro mode.
Once again, you have a delightful pearl and found a real treasure and I thank you for sharing it with us.