First, that is not a SIG 510-7 "T" (export variant in 7.62x51 to Italy; semi-automatic only)(510-4 configuration).
Recent prices have been as follows:
05.13.22 $11,750.00 (Fed Ord)
05.14.22 $10,575.00 (Benet)
08.08.22 $10,500.00 (Benet)(BUY IT NOW)
08.10.22 $18,125.00 (SIGARMS)(last of the factory-built rifles with test targets)
Pedro Bello, Fed Ord, and SARCO imported the fewest.
To the right collector, I would value at $19,500.00-$23,500.00.
Not the only NIB w/all in the U.S. , but very few in this condition.
Tony