Acquired this at the weekend (Lamport Hall Country Fair, Nottinghamshire). Although not gardening/horticulture related it is in the Dronwal sprayer catalogues identified as a Butchers Brine Pump. For injecting brine into pork or other meats I assume? Complete with inlet hose and filter, but no outlet hose and injector. It has a broken thumb screw clamp. I already have the Mysto version of this (although pump body only) that I bought a few years ago not realising what it was.
I stripped this down, and replaced the perished hose, leather pump washers (2), and split pins. I refitted everything back together – then refitted the lever again, the right way round!! It’s cleaned up a treat!