Sailing things right

"Danila, I need helb!"©®™

This is a helm lock screw.
The plastic cap is cracked and the metal rod isn't fixed anymore.
I need to fix it, preferably the way the unit will keep its current form but something reliable to last many years.
Best for me to be able to do this on the boat without the special equipment.

Solution I got in my head: crack plastic further, clean the center with Dremel, sand it with rough paper, fill the cap with epoxy and insert the rod.

Any better ideas?