A full torch / flashlight
Step 1: LEDs
Dismantling these was fairly easy, as shown in the pictures, it's not too dissimilar to 'breaking'
If you've got LEDs already, skip this.
Step 2: LED assembly
I've pushed the +ve electrodes through a small piece of insulation, cut from some heavy mains cable, like an elastic band this holds the electrodes together.
Also looped around the electrodes is a bit of thick copper wire.
The (yellow) insulation holds the electrodes in place while solder is applied, joining them to the copper wire.
A quick bit of soldering and you're done.
Next wire all the -ve electrodes together (see pictures). I've used individual copper strands from mains-cable, soldered and twisted.
Take a strand of copper (extracted e.g. from some mains-cable), tin it, tin the LED electrode and solder.
When you've done all six, twist them together, around the the outside of the central electrodes, to form a single -ve
Spend a bit of time getting the LEDs correctly aligned here. You can tweak and nudge the LEDs so that they form a nice alignment pointing in the same direction, but it takes a bit of time. Once you've got this to your satisfaction, it's time to move on to the next step
Step 3: Casting the head
Holes were drilled for the electrical connections, and I tried to seal up with Blu-tack (worked OK, but did leak a bit).
Regular resin for glass-fibre was poured in, and left to set.
The mould was cut away, but I could probably have forced it out.
Last (on this step) I've soldered a switch onto one wire, and a battery-contact onto the other. Both of these came from another horribly-cheap LED torch, which never worked (freebie)
Please see pictures, they are annotated