josephbwI took a flat toothpick, broke off the pointy end, and inserted it into the hole followed by the screw. I've never had that process fail me in all the years I've done it.
-Matt
Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.
I don't think I've ever had to remove one after performing that operation. If it was me, just to be safe, I would just break off another piece and start over. You are still only into it for less than a penny.
Joe
I was thinking from the prior description that the screw went down the stack. You could drill to the bottom of the stack to get a good tapered seat... in which case you would just let the bottom of the tubing piece 'center' as it bottoms.
If you have a 'rib' or other irregularity, file a notch or cut out the side of the tubing. The 'rest' of the periphery should hold it.
Note that the 'toothpick repair' will be more permanent if you use a little white glue or Ambroid on it before inserting in the hole. Put a drop of corn oil on the screw end before inserting it, or use some other release agent, if you don't want to wait for the glue to harden but don't want the threaded end to stick hard to the repair.