This 1930s bicycle saddle was recovered in the 1990s, the person that covered this one passed away many years ago.
Originally these saddles were formed veg tan top and bottom, with a layer of canvas between the leather and (felt or sponge rubber) padding on top and leather and metal pan underneath.
This saddle was not reupholstered as original: the leather was wet formed then glued to neoprene padding.
Here's what someone has suggested as to why the leather cracked in this way:
"Although I do like the looks of veg tan leather...which is typically soakedso that it can be 'formed' to the contours of an object or seat pan, the inherent problemswith the process is the soaking. The leather...has a tendency to'rot' or decay from the inside out, the side of the leather that comes in contact with the seatpadding etc. I have seen a number of...saddles that have had the 'cracking fromwithin' occur. bummer. You are looking at the result of the process when it goes south. Thorough drying once covered is key to avoid thepotential for what you're seeing in the pix, but still no guarantee."
I've done a fair amount of wet forming, talked to many leatherworkers, and have read many articles and books on leather and leatherworking.
Never have I encountered anything to support the assertion that what said above is true.
Can anyone shed some light on this?