Heppell registered RD 346543 on 17 February 1880. Jenny Thompson describes it as “(coal scuttle shape)” but I don’t think I have ever seen a marked example.
An online search of the summary from TNA simple reveals the design as having “no subject”.
Perhaps Paul S. has the particular design representation for RD 346543 among his collection, because that may well be definitive evidence one way or another. .
By the way, Jenny Thompson page 18 lists a total of 16 design registrations from Heppell between 26 August 1874 and 24 November 1882, (the ubiquitous coal wagon, fish jug, shells and dolphin series among them) but only the coal scuttle shape seems a likely candidate for your coal bucket.
Almost certainly not Sowerby (at least on the evidence of extant catalogues and pattern books). I suppose it could be Davidson or Greener, but this is the first time that I have seen anything resembling your coal bucket (especially in that amber glass with a wire handle).
Intriguing – thank you for showing it.