No maker's mark on the shank
S.L over S.L (unknown to me) stamped on the band with marks for Chester 1916 and push tenon stem stamped SOLID RUBBER.
By 1916 moving away from the more complicated and impractical bone screw tenon to be replaced by the vulcanite push tenon.
Seems strange to me that it took some thirty years after the invention of vulcanised rubber in the 1840s until the 1870s before its use for pipe stems was recognised as a good idea especially considering push stems into army mounts had been around since at least the 1880s.
+ Robert Lewis WINGFIELD MIXTURE