Base for a slimline water butt (Headington Quarry OX3)

Can anyone use these four plastic feet that interlock to form a base for a slimline (100 litre) water butt? 28.5 cm (11.25 inches) high from ground to support area, excluding the outside ridge. They are new as they came with my water butt, but were a bit too tall for the location where I installed it. Collect from Headington Quarry, or I could probably deliver in Headington/Cowley.