You are probably okay, but what happened was that when unleaded came out a lot of owners had their engines retarded to run on the lower octane fuel. I ran GTIs at the time and on 95Ron unleaded they were sluggish. So I had them advanced back and ran them mostly on Texaco CleanSystem 3 97Ron (at the time) with excellent results.

My advice is, after making sure that your timing is advanced to take advantage of 97-99 Ron petrol, I would run the car on it, preferably Shell V-Power because overall that's the best these days (there's no need to advance/retard with more modern cars because the ignition advances and retards automatically).