Robert.Hi. Iv’e got an Australian HERCUS 260, which is the 5′ model. Its much more modern than the earlier 4.5′, which is very similar to the South Bend, but they still use the same gears for the gear train, The problem I had, was, that I needed a full set of gears. So that I could cut imperial on a metric lathe. So as mentioned in previous threads, I used a 63/64 combination, The two used machinery places I went to, had lots of gear for Hercus Boxford, and Colchester, I did not have a gear tooth gauge with me at the time, BUT the Boxford gears looked different. ie, different DP/PA, The Hercus/Southbend used 18DP and 14.5 PA, although some of the later Southbends used a 20PA, if I remember rightly from two years ago, All very confusing.!!!Getting the right gears is fraught with problems, Tony at Lathes is a great help. Also last year on E/bay there was a chap in the UK who was selling off gears and lathes cheaply.
Best of luck, and if you know someone with a similar lathe to yours, so that you can measure DP/PA, it could save you some trouble with broken gear teeth. Buying of e/bay is like buying a pig in a poke if the seller does not know the right PA’s.
John Holloway