The chip in place 2.

Mine rests against the boiler weight, supported by the thin strips of card - these need to be painted black because they can be seen below the boiler body.

A strip of insulation tape is wrapped around the wires, which effectively holds the chip in place. The Yellow, Blue and White leads are for front and rear lights, which I haven't bothered to wire in. It is possible to use the chassis for the negative side of the bulb rather than the blue wire - the bulb gets only a half cycle of power, but the effect is not noticeable.

There is room above the motor to accomodate the loose ends. Note the card / black tape cover over the motor to ensure that the wires do not get rubbed by the worm gear.