The NZ pattern carrying handle didn't appear until about 1980, the earliest photo Ive seen is on a rifle in Rhodesia/Zimbabwe where the Kiwis were there for the independence change over.
How frequently are NZ pattern carrying handles found on Malay contract rifles? its possible they have been fitted when the rifles were imported into the UK? a large quantity of ex NZ L1A1 SLRs made it out into the wild, about 7000 were sold to CAI and from there they were turned into parts kits and also sold elsewhere as complete rifles. A lot of NZ rifles had the carrying handles removed by a directive, the carrying handles to be replaced with a neoprene washer.