I thought it was about time I got back to some modelling. My arm/shoulder is still recovering, but i have sufficient movement to use small tools, etc., without over stressing it.
So, I decided to fit the DCC chip as part of the finishing off process. This required separation of the chassis from the body, taking care not to damage the paint or weathering. That's not to say some minor touching up will be required by the time I've finished. The chip used is a Digitrax DZ126, the current nearest to the DZ123's I've tended to standardise on in all my recent locos. The (spare) lighting wires were cut off close to the encapsulation, just leaving the four traction related wires. Actual fitting was very easy as I had already fixed four copper-clad pads to the side of the gearbox, one each for the two pick-up connections and the motor terminals. In the temporary DC operation, short bridging wires linked the relevant pads to connect the pick-up wires direct to the motor. It only took moments to un-solder the bridging wires and connect the appropriate chip lead. The chip will just rest freely inside the boiler/smokebox when the loco is reassembled.
The photo below shows the attached chip and chassis.