Adding a keyboard tray drawer

Going with the study remodel and tidy up...I retrofitted a keyboard tray drawer (from a shelf) which would allow me to sit further away from the table when typing.  It saves me from knocking my knees against the computer equipment under the shelf which holds the monitor. Pic 1 is the original set up.  Pic 2 is the shelf closed. Pic 3 is the shelf open.