Pair of vases with engraved shells, trench art, WW1 trench art

Hello, I am selling the pair of shell casings shown in the attachment. These are folk crafts or trench art, dating from the First World War. They are in good general condition, traces of use, and measure 22.5cm in height. The shell casings are engraved "souvenir" and "cambrai" and bear richly decorated initials.