The ébauche for this unusual watch was supplied by Marius LeCoultre, using his retrograde date system as well as the unusual four letter abbreviation for the calendar indications.
For a detailed note on Marius LeCoultre see lot 298 in this auction.
Charles Ed. Lardet was active in Fleurier, Switzerland, during the last quarter of the 19th century. The company specialized in watches for the Spanish and Turkish markets.