I first contacted South Bend directly.They referred me to Grizzly.Grizzly is the distributor for South Bend.These are NOS South Bend parts(that I got).
Understand,when you give them your serial number,each of these old lathes has still the original build card attached to that SN.They pull the original build card for your lathe.
You can buy a copy of it.
South Bend is still making machines.They are in the Grizzly catalogue.
FWIW,Grizzly sells Bartlein barrels,some chambering reamers,etc.
One very rare thing I did find.A South Bend heavy 14 by 30 in lathe that is not a gap bed!!.Pricey...from Grizzly,15k.
Not promoting Grizzly,just sharing info.
If you search "South Bend lathe parts "or "Vintage South Bend Lathe parts",you will find the same trail I did.
Thank you for the other sources.