One thing that you cannot test easily is effects related to the surprisingly low impedance of UK 240V supplies. UK sockets - closer to 250V - are wired with a ring main, so each socket sits on a loop of wiring that has two paths to the fusebox. This approach means that the wall socket can deliver a LOT of inrush current.
Therefore, any bridge rectifier- capacitor combination has to be ready for such an inrush. It can blow diodes, even beefy ones. This is why you will often see a thermistor in series, to limit this inrush.
I discovered this the hard way, witha CRT design where the degaussing coil was across the rectifier bridge. This approach converted the bridge into a voltage doubler for a couple of cycles. In the US, this didn't matter on a 240V transformer supply.
In the UK, it charged the capacitors to 800V - and took out the switch transistor, and blew the DC current limiter resistors into dust.