I had a lot of disappointment chasing Plum Dinger till I found
Eastern Auto Paints of London Drive Bayswater Vic. (www.autopaints.com.au)
I had gotten several samples from different paint shops that differed markedly.
The chap at Eastern Auto Paints (ex Bill Patterson Cheeny) has access to the original paint swatches (post card size in individual envelopes) that paint can be exactly matched to.
Two pack tinters are a little different to the old acrylic so eye matching by a professional is the only way to get an original result.
I know you are in SA but I can assure you they will give the very best colour match available.