Pistol with a cap lock

steel: lock, cylindrical barrel, longitudinally threaded inside, double marking "100" on the underside, decorated on the sides of the lock with an engraved stylized floral motif, folding trigger with engraved decoration; handle ebony wood decorated in relief - with palmettoes (at the lock), longitudinal streams (on the handle), at the end of the butt a steel mount; overall length 16 cm, weight 199 g, caliber 0.9 cm.
Belgium?, 1st half of the 19th century.