Hi what is the value of a set of 4 x 1897 VICTORIA CHARITY 2 1/2d BROWN still joined, with minor perforation breakage

by Andrew Rushton
(Cairns,Qld, Australia)

Unlike the attached picture which is just an example for identification, I have 4 of these joined together in a single row. they are In mint condition, with the outer two stamps having a light hinge remnant. The centre pair have the top 6 Perforations broken but the rest is in fine condition.

I have not seen any joined examples of this stamp and I am wondering if it is more valuable as a set or individually, the current catalog value for an individual stamp in MNH condition is about £137 or $200 Aussie dollars, what would be the value of a set of 4? Would this be considered rare or scarce?

Thanks for your help

Kind regards
Andrew Rushton
Australia