380SL single-row vs dual-row timing chain (the 'ticking time bomb')

The V8 380SL's early single-row timing chain is the most-cited fear on these cars, later superseded by an updated two-row chain. Commenters disagree on the exact cutoff: one says the affected cars are 1981-1983 with two-row from 1984-1985, another insists only 1981 380SLs had the single row. …