This is one of my favourite tribute medals. My example was purchased from DNW in 1996 and is complete with its original fitted case.
The medal is named to Pte John Dunn (no relation) who is 7029 Pte John Dunn, York and Lancaster Regiment from Barnsley. He was a member of the 2nd Volunteer Battalion and attested for war service on 23rd February 1900. He was discharged on his return from South Africa in February 1902. The case has no space for the brooch pin on Crosland's medal, which is presumably a later addition.
The presentation was reported in The Barnsley Chronicle, Saturday August 30th 1902 where the recipients are listed as:-
16 medals in total. All the recipients were described as "Returned Barnsley Volunteers", presumably all Volunteer Battalion Yorks and Lancs Regiment.