First off, let me say that I really wish I had better Imaging skills and/or equipment..... Let's see how many of you folks can nail this one down!
I love the small white Anacs holders, and, I think most Morgans in them are very accurately graded and/or undergraded!
I have a 1902 O in a small ANACS slab graded MS-65 and i think that's about right. I just like these holders. But im drinking bourbon so i like a lot of things right now.
Before coin collecting on a Friday night: Running the Saloons After coin collecting on a Friday night: Drinking @ home, saving $$$ for more coins!!!!
I love them as well. Plus they usually develop some nice color at the top of the obverse as well. I have an 1888-O in the small holder just before it became ANACS. The label simply says "Official ANA Grade". If it wasn't so weakly struck, I think it would be a 64+ - 65. It's current grade is listed as MS-63.
Yours is a pre-Amos ANACS slab, and is pre 1990 (or thereabouts iirc). Later white slabs are not quite as special, or at least to the point many like make them out to be. There's good and there's bad, and like any holder new or old, the coins inside need to be judged by their merits.