This is the second pen in a lot I got in the other day.
When I got the piston unit out this is what I had.
I was really not to sure where to go from here but I had a syringe laying on my bench.
And inside I found this.
This looks like the end of a piston filler.
I shaped the ebonite end to match this.
And then I had my new piston filler.
The body is quite see through and you can see the piston moving the length of it as well as seeing the ink.
First time I have ever tried anything like this so now with a bit of silicone grease on the rubber part it is as smooth as can be.
Now we shall see how long the repair will last.
I guess this is the same system that Bexley uses on their piston filler so I think it will be fine.