I though this would make a nice GTG coin but we've had so many of them lately I decided against it. The D over D mintmark is hard to show in the pictures but I did my best. PCGS graded it MS-65. It has a satiny pale golden color. It's really nice in hand.
Lovely coin! Have you had a chance to further narrow down which of the D/D variants it is? http://www.varietyvista.com/03 Buffalo Nickels/RPMs 1938-D.htm
That was a nicely struck coin and I can see the double D MM without even enlarging it. Great looking coin. My example isn't anywhere near as nice.
Best I can tell from the pictures, it appears to be this: http://varietyvista.com/03 Buffalo Nickels/1938DRPM002.htm