In the old days, if you were storing saddlery you could smear it with vaseline and wrap it up well but you'd have to clean it off properly before use again. Not to be recommended for regular use at all, far better with something like Koachaline or Flexalan if you need to moisterise it I would have thought.
Don't use vaseline as it's mineral based like baby oil so doesn't do leather any good at all . The best thing for storing leather is that stuff called Co Cho Line I think