How about NGC MS-66PL. (I hope its OK that I made a second post...as I noticed that others did as well).
OK...heres the last TPG company I can think of.....its SEGS ...Sovereign Entities Grading Service and the grade is MS 66
Still no winner. Both the Slab and the Grade have been correctly identified, but not by the same individual. So, let me give you a hint, this is an OLD slab (about 20 years old), and the company, as it appears on the label, is no longer slabbing coins. In the interest of fairness, anyone who has't taken a second guess yet may feel free to do so.
A combination of one of the following , PCGS , NGC ,ANACS , SEGS , PCI , ANA , ICG , NTC , ACG , MCCS , NNC , NCG , SGS , HCGS , NCS , INB , PGS , VINCENT2920 GRADING SERVICE , and , MS63 , MS63 PL , MS63 DMPL , MS64 , MS64 PL ,MS64 DMPL , MS65 , MS65 PL , MS65 DMPL , MS66 , MS66 PL , MS66 DMPL ,plus (*) star , plus possible toning noted. !! Most likely ANA .