When I was replacing segments on my trailer I looked at a lot of ways and bought a few tools to try. In the end I needed close to 90 lineal feet of this profile produced. I chose to have it done and It cost me about $1.00 per foot.
I have also noticed that the bead changes from factory to factory and year to year. I would guess the profile was a little unique to every person that made it. If your replacing segments I would consider taking the old one and the new blank to a sheet metal shop. Explain your dream, tell them about your trailer and have him do it