Taking on board what I learnt yesterday, I repeated the procedure of making the PCB. This time the PCB came out better than before, with no bad connections 🙂
Soldering went well at first; all LEDs, resistors and switches went on with little problem and all work as expected. The trouble came when I was soldering the jumpers. I wish I had thought this through a little bit more before-hand and used through-the-hole, but nonetheless it is now working. I used Sellotape and printer paper to insulate the underlying tracks and then soldered the jumpers. After a number of worrying failures and a little bit of lost copper track (fixed with solder), it was done.
The only concern I have now is that when I solder the bluetooth module to the pads on the right-hand end, the jumper will unsolder and/or break. Fingers crossed.