Many, many years ago I wanted to change the oil in the headstock gearbox of the Colchester Student lathe I used to own. The oil recommended in the 1953 manual was no longer available, so I emailed Colchester lathes who told me that I should use Shell Tellus 100. Unfortunately, I could only get it in 25 litre containers... I used about 5 litres, and the remainder has been sitting in my garage ever since. Now I see that outside of the bottom rim is looking a bit rusty so, if I don't shift it in the next year or two, I'm going to get 20 litres of fairly thick oil all over my garage floor!

I think it's reasonable to assume that it could be used in the headstocks of many lathes of a similar size and era, and possibly for the gearboxes of other machines (but you must use your own judgement). It's now listed as a hydraulic oil (not on my container) I assume that the properties that make it good for hydraulic pumps was the reason for Colchester Lathe's recommendation.

I have no use for this oil (the lathe went some time ago) so it's free to anyone who wants to come and get it - I live a short distance from the A12, about 6 miles south of Ipswich, Suffolk.

As for the current Covid rules - if you want to take it now we can arrange a time and I'll have it ready to pick up near the top of my drive; we can wave at each other from a long way away.
If you're not happy to get it just now, I can hold onto it - for a while - until the regulations ease a little. Anyone who's willing to collect will take priority over anyone who wants to put it on hold...

If all else fails it will have to go to the tip, but I'd rather that it went to someone who has a use for it.

might be worth posting it on here >>>>https://www.mig-welding.co.uk/