Flashing red brake warning on combo gauge, Photos added Options

[DaveO90s4]

Hi all,

1975 model, now with the infamous flashing brake warning light. I had the oem master cylinder and front callipers overhauled when I bought the car about a year ago. Recently I could hear the flasher unit clicking as I drove, and now this has 'grown' to the red light flashing too. I have confirmed that the park brake switch is working properly. I can stop the flashing only by disconnecting the wire from the reconditioned master cylinder. There is no reset switch on that master cylinder. I am very confident that the brakes are working properly: good pedal feel, stops straight and well, no residual pressure holding any brakes on, etc etc. I have no reason to believe I need to bleed air out of the system or do any other work on the brakes - other than for this flashing light issue.

I've done lots of searches, but other than for disconnecting the offending wire / switch ( which I'd much prefer not to do) I'm unsure what to do next. Maybe buy a new switch for the reconditioned master cylinder?

All suggestions very welcome.

Thanks

Dave