i think u can do something easy, but need a little hardware modification, you have to open your servo carefully and solder a wire to the middle pin of the potentiometer, then u have to "calibrate" your sketch using analogRead() function read the 0 degree state of the pot and the 90 degree state, use the map function to map your result to a variable call "time" and this variable control the blink speed of your led.
and use if == 0 and if == 90 to set de led on all the time.
i hope this help u 