My first vision tube cracked more then a months use in. (I hit the door jam rounding the hall, 2 crack at top and 2 lower opposite side) Ce2 itself still works so I grabed a 5ml BD syringe that the pharmacist just hands you if you ask (nice to give a kid oral meds with). and a #10 o ring from lowes.
Replace the clear o ring at base with the hardware stores cut syringe to size of tube.
Then yes "man handle" the part together. No glue and working wonderfully, no leaks. Rubber cup fits in on top too.
I will note the vision tip is loose in the syringe but if you fit a carto condom on it and trim it's a nice tight fit. Or a small rubber band for a seal? One hay of a sturdy unit now. Also can't use my cool vision cone with it, syringe to thick.