According to Colin Walker's Siege Register, apparently the Hulley family was an extensive clan of uitlanders.
Hulley, J.T., with TG. Hibbard states Hulley J.T. is the father of Hulley, P.D.
Hulley, P.D. with TG.
Hulley, P.W. No family lineage shown. With TG.
Hulley, Samuel R, with TG. No family lineage shown.
Hulley, W.T. shown as "Pte, 121 Bechuanaland Rifles". Discharged misconduct, no medal. Again, no family lineage shown.
Yes, I am surprised that Bonhams did not add more details to the lots. The FID group only has the information you supplied and says nothing about the Cape Naming. They did show the DCM at the last Britannia so time was not a constraint.