I have taken off the glue from the Letus because the FL was off and was always off since it was purchased from another member - who at least told me it was off from the start. I need the exact distance from the white plastic GG holder to the bottom of the plastic lens holder (to be more exact the length of the white syringe sticks from top to bottom), so I can glue this back in place.

Try this.

http://www.youtube.com/watch?v=yugfv4ZVXgg

the video shows about 40mm from front of lens holder to baxk of GG support.