Bill.....man, why didn't you come with a question that would hard to answer...lol.
I don't know...but that looks like toast to me.
I do a lot of leather work and once it gets to that amount of dry rot there's really not much one can do... perhaps some Fiebing's Liquid Glycerine Saddle Soap, available from Tandy's.
There's a lot of mold there too...that's deadly to leather. The liquid saddle soap with at least get some moisture back into the leather and
may prevent further dry rot...
You've got a job, my friend...
Tom I.