Most old performance cars before the '60's had fixed valve timing. The timing being set for optimum performance at high revs. Didn't sound to hot on start up...but did the business on the track.

We have a vintage 1940's aerobatic biplane on our airfield with the same set up. The engine is a solid lump of 9 cylinder machined iron radial with completely fixed timing due to the way it rotates. Sounds like a tumble dryer full of forks on start up but smooth as silk on 100% power.

fiat have upgraded the Variators now, so if you fit a new one it should last at least twice as long as the one you are replacing did

You could always fit an early bravo/brava cylinder head, they didn't run a variator. It would be a bit of work though.

New multiair head might do the trick. User programmable inlet valves ...... BANG!