300 Saybolt universal seconds is the viscosity required (300 SUS) which cross-references to ISO 68. So you need an ISO 68 oil, most of which at that low viscosity will be hydraulic oils.
Go to a Farm & Fleet type store, choices will abound for that common viscosity grade.
However, having gone through a similar exercise for several older lathes & mills, any sort of gear or hydraulic oil will likely work just fine. We replaced the headstock and way oils in several lathes and mills with a common ISO 150 gear oil we stocked in 55 gallon drums.
conversion table here
300 at 100F is in the ballpark of 75W85 gear oil, SAE30 engine oil, ISO68 hydraulic oil.
That has no bearing on the anti-wear additive, just the viscosity part...I don't think that sort of machine has much in the way of anti wear additives