Outback Suspension Coil Springs
Outback Suspension in Melbourne is a company that fits coil springs in conjunction to the existing leaf springs. They started doing the conversions in the 1980's and are still doing them today, mostly on Troop Carriers but they still do the occasional 60 Series. Basically they remove a few leaves from the spring packs and add a coil with custom made mounts. The older conversions were done using Koni shock absorbers.
Outback Suspensions can be found at 2/43 Vinter Avenue, Croydon and can be contacted on (03) 9723 3809
Screenshot from the now defunct website from 2015.