Jaegers 6" f/10 "GJD" OTA Construction - Focuser Backplate (prep to attach to main tube - 6)
 

Aluminum Tape filler strips being smoothed around Focuser Backplate - 8 (Click to see an enlarged image.)

 
Using the back of my finger nail, I smoothed down the edge overhang of the aluminum duct tape around the leading edge of the focuser backplate's rim. At the upper left of the picture, you will see areas I did not get to yet. In the end, the aluminum duct tape will do its job of filling the gap and by centering the focuser backplate once attached to the main tube. The overhang will prevent the tape from getting snagged when the two components are joined.