Don't have a clue, if it's weeping knock plug back and nip up see what you get. If you are changing the oil anneal it by heating to cherry red and allowing to cool.
Oil comes up as IYK500010 according to Rimmers
But yes, LR cat shows two transfer cases so I may have picked the wrong one
IYF500010 on one & the other IYF500030. Both of which come up as copper washers on other suspects incl Craddocks so I don't know why Rimmers goes to the oil.
If it's any help Britcar show pics of both against a ruler.