Pure Pt and dilute alloys of Pt-Cu and Pt-Au were fast-neutron irradiated at 4 K, and subsequently isochronally annealed from 7 K to 750 K. The recovery spectra obtained using a resistivity method were compared with spectra of the same samples predoped with fast-neutron-irradiation-induced defects which exist above 400 K. The results could be compared favourably with existing data on prequenched and irradiated Pt. A comparison of these new results with existing data relating to the controversial 120 K and 360 K substages in Pt allowed more positive interpretations regarding the defect processes occurring at these temperatures.