Virtually impossible to get variegation with leaf cuttings.

Here is a second opinion: Garden Hacker: Snake Plant propagation by leaf cuttings - "...propagation by leaf cuttings is very simple but is best done with the solid-green variety. Taking cuttings of the variety with the white-yellow edges (variegated forms) will revert and produce plants with all green leaves. The variegated Mother-in-law's tongue is best propagated by making divisions of the rhizome if you want to keep the variegated leaves."

Will be interesting to see what the Siam Silver cuttings will look like then if they take root.

Yes indeed - it will be interesting to see what Siam Silver produces from root cuttings. Please keep us informed!

Should look like metallica.