Of no help now*, but a half-century ago, my 1957 TR3A was fitted with an Abarth exhaust assembly. In my memory it was never harsh or raucous. it had a deep, melodious burble at cruise and a satisfying bellow at full throttle , the Pavarotti of exhausts. I made several 300+ mile top down trips to West Texas, and retained my hearing.
*Having written the above, before posting, I searched “Abarth exhaust systems” and found new, old stock Abarth exhausts are being sold from the Netherlands!
A TR3 system is still available (at a quite a price). There’s also a cockpit-view video that sounds (on my iPad) very near as I remember.