Already a very lovely rendition, Paolo. Really well done!
On listening to a performance conducted by Maestro Ennio himself, (catturato a Venezia, 2007), I was immediately reminded of the need for molto vibrato when using Dimension Strings in intensely romantic pieces like this one. But rather than waiting for VSL to agree to add molto vibrato to DStrings, I'd say embedding VSL string soloists somewhat prominently in various sections would more easily secure the right feeling for this piece.
If I were to render this I'd study several of the different recordings available on YouTube, and craft my own expressive and dynamic softenings, tightenings, shortenings, lengthenings, etc, according to what I felt worked best in those various recordings. But that's just me wanting (indeed needing) to avoid the very long and deep learning I'd require to compete with the best out there. That said, I'm fairly sure Paolo will do it Paolo's way, come di solito, lol.
But in any case, attaining the final 20% of the quality of rendition and mix will probably take about 80% of the time and effort - (Pareto Principle) as always, it seems to me. And as you're already so close to a marvelously lovely emulation, I'll just wish you buon viaggio.