Aye Smithy,
Solid state, encapsulated, all in one unit , with a big heat sink. May cost the combined price of the two old instruments and if it goes 'pop' will require replacing, no repairs. But they usually go on for years and never wear out or rattle to bits.
In 1976 when I acquired the Duke 450, electronic ignition, a 60w alternator and 6v electrics fed through verdigris green crimped connections at the ends of wisp like copper strands, encased in multicoloured spaghetti became my bĂȘte noire! Only the consideration and kindly help of a competent electrical engineer, using Ford Escort, modified points and advance/ retard unit, an MZ 250 coil, a + earth zener diode and a Triumph rectifier along with a complete rewire and 12v bulbs got the bike back on the road.
Keep it simple, solder every joint, rubber mount everything, be scrupulous with earth leads and vaseline or ACF50 well, use tinned wire of the correct amperage rateing and tinned connectors with insulators. Not cheap, but trying to trace infuriating 'shorts', in the peeing rain, with numb fingers, at the side of the M6 are a memory that haunts me.
Another is pushing the bike from Victoria Station across London, to Euston station after the electrics shorted, just outside Maidstone on a January afternoon. I had to get the train, with the bike, back to London from Hertfordshire the next day, to go to Liverpool and across to Peel! Ended up sleeping in a vacant ticket collectors box in Liverpool, with the heater turned up, afore firing the old girl up to ride to the Liver Pier on a jury rigged battery, with no lights, again in the rain. Queuing with the "judies" for a mug of tea and bacon roll with HP sauce, was an education!

All the best, with which ever way you decide to sort it.
My regards, Bill.