That is a pretty basic (quality stuff, but basic makeup) 220 R&O. You're gonna have a hard time going backwards on that one if you cross reference it. I suspect that the trouble is getting it in less than a 5 gallon pail?
If I assume that the lathe is over 20 years old (pretty new relatively speaking), with products and standards changing over the years, if you were better off to drop down to 150 ish cst. 100 would probably be fine, but I havn't got near what I need (Including the inscessent time this takes) to sort that out. is there a pump in there? If there is, make sure it's in good order, but if it is, you're golden. that's it. You could use an AW oil without second thought too. You'll never use any of the AW in that application, it won't even really see the conditions to "activate", but if it gets it in useful quantities, it's not gonna hurt anything.
That's a very "industrial" oil to find small quantities in, but in the brands I'm familiar with, Shell Harmony, Phillips 66 syncon, and Chevron regal would be premium products, if any of those are near you.....