View attachment 22884 I have rebuilt a couple of these.
It is best to find some plastic of the same type. Newer ABS does not work as well.
It is best to make a pattern to keep with in the proper size but there is a little leeway for over size.
Build up the end with a wood burner making sure the plastic is completely bonded together.
You want it slightly larger that original so you have room for filing and shaping.
I then used some .010 brass shim stock to shape a cover around the plastic.
I had brass tubing on hand for the hole but you could roll a tube of the proper size with the shim stock.
Once you have the brass molded around the plastic float some solder around to hold the metal in place then file smooth.
You might need a small clamp of some kind to hold metal together where it overlaps while soldering.
The metal is so thin you do not need a big soldering gun to get the solder to flow.
The heat during the solder will help bond the metal to the plastic but be careful not to get it so hot it melts the plastic to the point of collapse.
I have used tin from paint thinner cans for projects but prefer brass for this type of project.