Many thanks to you all who replied to my request.
Peter put me back to Charlesworthmouldings were I had overlooked his listing for Morgan cars as he did not have a photo of these.
Sorry Jon but at 82 I do not have the skills to put up a photo of these rectangular warning units. However Melvyn Rutter has a 1991 plus 8 for sale on line which shows these warning light units.
As I also have to replace my tired alternator I will ask Melvyn for advice. No charging problems with the alternator but bearings are noisy but at 180,000 miles I cannot grumble. Perhaps I could get the unit rebuilt with new bearings but at the price from Melvyn and the 3 year warranty on the unit may end up the same price.
Never a dull moment owning a Morgan. I felt sure that people modifying their dash and panel lights would have these units lying on a shelf in the garage.