So it appears that about 6 years passed between the rug theft and the murder of Fanucci.

If Vito was 9 when he came to America, and Santino was born in 1917, then Vito was approximately 32 years old when he murdered Fanucci. I'm guessing Vito was about 5-6 years older than Clemenza and Tessio.

In the movie, it appeared that Vito (Brandon) was older than Tessio and much older than Clemenza.