Glad to read there is an alternative to 'Castrol RR363 in the USA from GRM and they do boldly put on the front a warning. 'Harmful or fatal if swallowed'
When I worked at Jaguar/AM under Ford ownership it was compulsory under health and safety ISO/BS standards that everywhere liquids were used or stored we had to have a 'spill kit' and complete content specification sheets supplied by the manufacturer of the contents of the liquid so in case of any accident this could immediately be supplied to a surgeon, doctor or hospital.
So we somewhat got to know what these liquids contained and especially useful as Castrol was a preferred supply changed under Ford ownership from what was previosly Mobil would have been seen on cars like the Jaguar XJS Le Mans winner.
I did watch also from these spec sheets the supply of Castrol GTX slowly diminish its ZDDP content another concern for many classic car owners.
My understanding Castrol have sold/given their original formula to Bentley. I am not sure what Bentley have decided to do in marketing any of this.
Several 'home brew' suppliers have adopted the use of the term RR363 obviously claiming it was specified by RR/B when in deed it was actually 'Castrol RR363' that was specified.
A bit like the old Coke Cola wrangle many years back and perhaps a little loophole with these homebrew suppliers just using the term RR363.
At the conclusion I know many RR/B owners and friends who have been using DOT3/4+10%PG castor oil for well over 10 years and some having clocked up over 50000 miles in that period.
Is there also some other secret ingredient Castrol put into their RR363 that these homebrew suppliers know of..........now that I don't know
I still have two litres of original Castrol RR363 in the litre tin containers and two litres in the plastic bottles. When these have gone I will be speaking with my chemist or beautiful ladies at the town massage parlour and get some castor oil and make up my own.
BTW castor oil is NOT poisonous.... we used to be given a large spoonful as children many years ago if we had a poorly tummy trying to wag a day off school. Trust me you would never complain again.
All the best