Chile 1861 10c Colon Bisect Folded Letter S. CARLOS Straight-Line to Bulnes

Folded letter, with contents, franked with 1856/61 "Estancos 10c deep blue, diagonally bisected, tied by target handstamp in brown, with "S. CARLOS" straight-line in matching watery ink alongside, red "CHILLAN / CHILA" transit at lower left (Jan 2), light unobstrusive filing folds, the adhesive with remarkably deep colour, a scarce and desirable franking complemented by a scarce straight-line.