I've seen one source that gave the mark(red enclosed) as a Definitive stamp from 1879 - 1885/1886 with the pairing of the Crown over Crossed Palms St. Etienne(blue enclosed) being the Provisional proofmark. So either way the use of this mark should bound the date of production?

Where is this term "HOYAU ETAMPES"?

Kind Regards,

Raimey
rse