Progress so far. Given that UK ruling dictates a rear fog light must be at least 100mm from stop lamps, I'm leaving it in situ and placing reversing light in pod on top of running/stop lights.
The three mounting ears of reversing light obtained
here were cut and filed flush with mounting shoulder, allowing it to sit on matching shoulder inside pod supplied by my dealer. It was found that heat sink touched rear of same though, but careful profiling of the outer edges of heat sink allowed it to seat fully, secured by the push fit pod shroud which holds lamp firmly in place. I know airflow around heatsink will be limited but the lamp will only be used for very short periods.
A 30mm length of M10 x 1mm thread hollow studding was obtained from a light fitting supplier. Matching thin nuts and thick rubber spacer/washer complete the mount needed to fit onto running light casing.
After fitting will extend wires from four way rear light socket to running light casing, which should provide gearbox switched power feed.
