Ebay can net you some low carbon ***** that are quite easy to drill. They can be had in 7/8". I bought some smaller ones for a coat hanger project and they drilled quite well. Quite the brainstorming in this thread.

 

I've seen a TV show about making brass instruments where a series of progressively larger steel ***** were lubed and pressed through the tubing to round it out and expand it to size. This should be possible to imitate, maybe with a long piece of threaded rod made into a "puller" to force the ***** through the bed roll.

 

The only thing I could argue is brass is way softer then steel

 

....Very carefully slice the damaged roll off with a die grinder/cutoff wheel. Try for the very top of the roll. Don't use a torch ... too much warp. Then weld on a piece of exhaust tubing of similar diameter. Mig welder, stagger your welds as to avoid over heating. Grind smooth, skim of filler, primer. ...........
Stan. ........

 

If I was going to do the body work etc. Which I'm sure I will do eventually. I will do that probably. But looking to clean up the bad spots without welding grinding etc. My truck has 66 year old "paint" and will stay like that for a while so I can enjoy it a bit. When I build my shop I will do a complete resto/mod.

 

Only problem I see is that the bar would not exert enough force as it would get absorbed in the length , think of it like a chisel . Nice and short maximum force the longer it is the more spring or flex the metal has and He less force on the ball

 

Having the ball drilled fully through and threaded gives rod on both sides allowing you to push or pull as warranted. Stu

 

Could insert the ball from one side of the damaged spot, attach a long rod to a dent puller and "pull" the ball through the damaged area....maybe

I know there have been some on here who have made there own bedsides(much easier to do on the 50 1/2 and up bed with the smooth sides) who have use tubing to weld on top of the bed bedside to mimic the original roll.

When I got my truck one of the bed sides had been slumped over for bout half of the length. I fabbed a lever to grab the bedside and was able to work it back into shape

 

Question I have is why are you talking about drilling and treading a ball? wouldn't it be better to have it free to roll? I also thought it would be better to split (cut) the top of the roll to allow you to pull and hammer the roll and then weld the slit back up after the rail is repaired