I live for the CABE
My nieghbor who has a 1928 Hawthorne Flyer with G&J steel rims was thinking he'd trim about 1/16th off the inside edge so the edges would butt up against each other cleanly and hug the tube. Working on the second tire we found the tube was getting pinched in a few spots where the inside edge of the tires met. I put about 10 pounds in the tube to get it on, then had to let that out to put the tire over the tube all around. There isn't much wiggle room for get the tire edge over the rim if the tube is supporting the tire and holding it out form the rim opposited the side your working on. Started tucking one side in then the other. Then started turning/tucking under the edge to seat the bead in the rim.Yeah, as a helpful tip, for the guys using these tires, I use a paper hole punch to notch both sides of the opposite edge of the bead, where the valve stem goes.
I put that notch below the area where the PSI information is on the sidewall of the tire.
It reminded me of some sewing and knot work I've done on large schooners I've worked on, we would have described it as capsizing the edge to tuck it in and under the tube and popping the bead into the rim. Once that bead is seated I was really impressed with the effectiveness of this 120 year old technology.