Success!     While the above is not pretty, it finally worked.  The layout is the same except that the transistor's pins did a 180.  When I jump PR +5V_SB to the far side of the 10K attached to the center pin, the hard drive connected to the PS fired right up. I will try to get soldered up and tested in the IIsi soon.   @superjer2000 I appreciate your guidance on this.   To those on holiday today, Happy Thanksgiving!