This may help if you decide to go the buzzer option.

http://www.gomog.com/allmorgan/+8WiringFront.pdf

https://www.ebay.co.uk/itm/CAR-INDICATOR-WARNING-BUZZER-A-MUST-HAVE-/252651891201

Three wires on them normally one black and two reds. The black of course is the Earth and one red needs to go to the Green/White and the other red to Green/Red off the switch itself or anywhere convenient .
The bike one's are good and loud.


2009 4/4 Sport Henrietta
1999 Indigo Blue +8
2009 4/4 Sport Green prev
1993 Con Green +8 prev