Fix one thing, another breaks.
Flicked on the indicator, it looked like it was operating poorly and with an erratic rhythm. 3 seconds later, I could hear the fuse blow. Sure enough, a peek under the dash showed a blown 20A fuse. Before beginning the diagnosis (which would end up being by trial-and-error and unlimited number of new fuses!), I ordered some thermal .... fuses which can be reset if blown.
Some priliminary investigation, discovered only the left-hand side indicator was affected. After looking at the front indicators (which has been "disturbed" by me recently), disconnecting the front bulbs, nothing changed. On a hunch, I disconnected the loom to to the rear lights, located down a crevice on the left side of the trunk. Bingo! front indicators back to normal and that indicates (pun!) the problem is on the rear wiring/cluster.
Pulled off the rear light panel. Found some unshielded lose wires left behind by the mechanics that fitted the car for european style rear indicators. At this stage, the fault seemed to have rectified itself so I insulated up the lose wires, put everything back together and called it a day.
Indicators have been working fine since.