An old pair of shoe from my grandfather, crackling; but I just want to make sure it doesn’t get worse!

I've had the shoes for a while now and their very important to me.
Though when I've taken them to shoe repair places, I was told there was nothing I could do for them.
I'm attaching the pictures of the shoes.
I don't mind the appearance of cracking; I just want to make sure it doesn't get worse.
I clean and lotion them, but they're an old pair from my grandfather.
Before they were given to me, they went some time without lotion.

Thanks for your time. I look forward to hearing from you.

John.

#1
http://i300.photobucket.com/albums/n...eCrack-277.jpg

#2
http://i300.photobucket.com/albums/n...eCrack-278.jpg

#3
http://i300.photobucket.com/albums/n...eCrack-279.jpg

#4
http://i300.photobucket.com/albums/n...eCrack-280.jpg

#5
http://i300.photobucket.com/albums/n...eCrack-282.jpg

#6
http://i300.photobucket.com/albums/n...eCrack-283.jpg