Apart from lever engagement of the power sliding and surfacing feeds (replacing the screw-in-and-out knob) the later-model South Bend Heavy 10 was largely unchanged mechanically.
Above and below: a South Bend Heavy 10 lathe purchased in 1961
The South Bend Heavy 10 lathe as sold in 1991. This example was discovered in 2024, the original owner having kept it in immaculate condition