[rsk289]

Very tough to pin down. It's perfectly possible that AC chose to go to amber lenses early. They would have known the change in requirements was coming. Personally, I'd match to the rears as I suggested. I can't think of any Brit car of the period that had flashing red (dual-purpose) lights at the back, with an amber indicator at the front. It would be white front with red back, or all amber.