Tin for round roof shed

Take off an old sheet as a pattern and take it to whoever you decide to get. Also measure the individual length of the 3 sheets. The top sheet can be a different length to the 2 lower sheets. Neighbour got sheets rolled by a company and the curve was way too severe. Luckily he was told a shed builder had an old rolling machine. He was able to recurve the sheets but it was a dose. Something like 60 sheets each 10 ft long. There was a batch of cocktails sheets to be done as well. Sometimes it might be worth altering the lean to timbers to do away with the cocktails sheets. They use a flashing to close the joints between the 2 roofs.