Holy Grail of Athearn SD39's! Hard to find.  Two ANDX Rio Grande SD39 4027 & 4028.  I installed non sound Digitrax DCC decoders in both, set to road number. The 4027 looks new, while the 4028 is like new.  The 4027 has front coupler pocket glued in place, but still moves back and forth.  Both run great, with lights!