Another day in the workshop.
Yesterday I bolted the latch to the door. But how to attach the catch to the surround, and the restraint to the door. The plans call for tiny screws, but that method did not appeal. I decided to silver solder them in place. Silver solder is immensely strong, and does not require tapping and threading minute screws into position. The problem with silver solder is that some parts of the firedoor are already silver soldered, and I did not want to risk undoing that previous solder.
So, I used a heat sink.
The next job for today was to machine a strip of metal 6mm wide, 2mm thick and 600mm long. I decided to make it from brass because I have a sheet of brass the correct thickness, and I was already thinking about the tight bend which was going to be required.