So here it is wired in. Leads are deliberately left a tad long. Better too long than too short !

After writing this, the red lead broke from the DCC circuit board,and the grey lead broke from the brush cap. The grey lead was easy, I had left enough length spare to re-strip and re-solder - but you have to remove the cap from the motor - the body underneath the cap is plastic !

I successfully resoldered the red lead to the DCC chip using a ground down solder tip. I tinned the tip and cleaned off all surplus solder. I taped the chip onto some tissue paper which I soaked in water, and pressed the chip down so that the underside circuits components were wet. I tinned the red lead, and held it in place over the tiny blob on the board. Watching with a magnifying glass, I lightly touched the wire with the fine soldering iron tip until I could see the blob underneath melt, and then removed the tip and let it cool.

The chip takes a while to dry out, but the water had done its job in preventing heat from damaging the tiny components.