Just to post (and yes I got the oil tip from pst) to say, anyone has any desperately dried out leather that you think is at deaths door, I strongly recommend getting some effax lederöl (leather oil). I didn't think it would be as good as it is 
and bought it for the soles (done a treat on those) but from having boots that were set like concrete, I've done a few applications to see and already they're flexible and not cracking (which I was concerned about). Cost me £6 for a bottle from the local tack shop, I thought I'd used loads earlier to find I've hardly touched the surface of it, well worth it as I'm going to have loads left for other things 
. They(effax) also do lederfett in humongous tubs for £7 (though prices are what I paid maybes different at other shops) that will keep me going for some time and is way cheaper than poxy lil tins of dubs all the time 
.
Right off to find all the dead feeble bits of old leather we have and give them a going over.
Edited to add, it I put it on a pair of boots that haven't seen any sign of tlc for 60 years, and when I say concrete I mean they leather had dried that much they were rigid, just incase someone puts words I didn't put in reply )
