They’re nice things and an essential accessory for inclusion in any cased Webley pistol set. Finding one in good condition is also getting harder these days and rarity will always have an affect on prices.
A friend of mine who was part of the Arms & Militaria team for a major auction house once told me that although his office clutter included many rare and expensive items, the one that always gave rise to the most interest was a 1960s Webley oil can.

Brian