[Lynn Eades]

I have used 4140. It work hardens. I used steel from broken shafts that were so hard, at the break, that a ceramic tip wouldnt put a mark on them.
I made mine on the lathe and finished them off with a die grinder. (my formal lathe training was mostly while the metalwork teacher wasn't looking at school)
The small one, with the handle was rolled into place behind the rivet head to do the ones going through the engine bed rails into the floor. (we are yet to do the second one) We have done them with the carrier on its side, introducing a dolly behind the handled thing.(on the outside of the bed rail)
If you are planning this operation, look for a friend who is an insect, or even better a spider. If you ask your wife, she might point you in the direction of one of her ex boyfriends.
Anyhow the point is, they need extra arms/hands etc.
We have cut the rivets to length for each set of rivets. I heat a rivet, pick it up with pliers, and poke it into the hole. My friend with the gun pulls it in while I position the dolly. I yell "ready" or "go" (this is optional. I'm sure Richard, that you will have some weird local alternative)
With that heavy dolly arrangement in the photo, I get it behind the rivet,get my knee behind my elbow, and my foot against the inside of the hull on the opposite side. It works good that way.
Try not to put rivets in the bolt holes for the bogie adjusting studs. They look good, but slows your progress down.