[botport]

I do not think you can leave this card in the GAI holder. My feeling is that as long as it is in that holder you will be hamstrung as to what you can get out of it, whenever that may be. My guess is in the GAI slab that you are looking at a really nice SGC 'A' or possibly as high as an SGC 2/3 value.
I think the opinions shared earlier will be the prevailing thoughts of potential future buyers (ie: Its trimmed - I will pay 'AUTH' price)

Not many people will buy the card and not the slab at 100k+

I am not claiming to be an expert but here is my amateur assessment. This card has a good chance of grading numerically. I have seen plenty of T206 with equal or less borders with numeric grades.

To me the downside of having it regraded is negligible because of the stigma of the current holder. Meanwhile, the upside is huge.

In sum, to me the worst case scenario is this comes back as PSA 'A' ... and that would be disappointing, absolutely. However, until graded by PSA or SGC I feel you will be hard pressed to realize more than what Authentic PSA and SGC Cobb bat offs routinely sell for.