None of the Blue Book references list production numbers for the any Sig Series guns. Since they were made by Iver Johnson, Henry Repeating Arms may have numbers.
FWIW - 2nd Generation Colt BP items were made by, marketed by, and warranted by Colt. Colt had nothing to do with the Sig Series except for licensing the name.
Fingers (Show Me MO smoke) McGee - AKA Man of Many Colts - Alter ego of Diabolical Ken; SASS Regulator 28564-L-TG; Rangemaster and stage writer extraordinaire; Frontiersman, Pistoleer, NRA Endowment Life, NMLRA, SAF, CCRKBA, STORM 327, SV115; Charter member, Central Ozarks Western Shooters
Cynic: A blackguard whose faulty vision see things as they are, not as they should be. Ambrose Bierce