My Grass Machete had a touch of rattle, which I knew about before I got it. The play didn't bother me at first, but I eventually decided to fix it.
I tried drilling the lanyard tubing, but it started spinning. So I pressed it up enough to cut off one end with a dremel sanding disk.
Going back, I used a part for a Coleman lantern (shown below). It's brass, already flared on one end, and almost the right size.
I had to open up the lanyard tube hole in the tang just the slightest bit, and did so with a little Dremel grinding bit. After that procedure, everything went together fine.
With a healthy dose of epoxy on the blade, I slid everything together, cut off the new brass tubing with my sanding disk, and flared the other side using a hex bit.
Good as new, no more play in the handle. Below, you can see the difference in color between the two lanyard tubes.