I love working with styrene - it's so forgiving. There aren't many materials that allow you to make invisible joins in so easily.
The design of the South Eastern Finecast arches combined with the way I've used them on Selly Oak lets the end of one arch be visible where I don't want it.
The bricks are laminated to a 2mm thick backing sheet using Limonine solvent. To hide the end of the arch, I carefully cut out a section of bricks and a matching strip from a plain sheet. Then the whole are is washed with Mek-Pak.