Color issue on overly-ambitious project

[Minerva]

I'm a total newbie, so forgive my ignorance - I'm trying to fix a chair (see photo). My problem is that the heavyweight hide I purchased has become unevenly discolored by exposure to light. I weighed it down with books to flatten it for a week or so because it was tightly rolled up. It was inside, but had limited western sun exposure. My plan was to use neatsfoot compound to allow it to darken and soften a bit. (As an old horse-person I always liked how that worked with tack.) But then I saw that the leather darkened except for the areas where the books were. I called Tandy, where I purchased the whole hide, and they said that even dying the leather might not help with this two-tone problem.  Has anyone had an issue like this? Do you think neatsfoot compound would help smooth out the color differences? What about putting it outside in bright sun?

Additional photos with more detail at the links:

 Chair I'm fixing (for context) https://drive.google.com/file/d/0B1x9mbciSM17QzM0dnZ6aUVvWGM/view?usp=sharing

New leather closeup of a problem area: https://drive.google.com/file/d/0B1x9mbciSM17SkdUMnRiMVBSN00/view?usp=sharing

New leather, view of whole hide: https://drive.google.com/file/d/0B1x9mbciSM17YkhRMk5uMHlVMDg/view?usp=sharing

Many thanks!

[Northmount]

You can try bleaching it with oxalic acid.  Have had good results with it.

There are several threads on oxalic acid here if you care to do a search for them.

Tom

[Minerva]

Thanks for the pointer. I think I read every single post on oxalic acid. I tried it on the edge of sun-bleached areas and it did not help at all. It seems that the discoloration is deeper than just the surface.  The worst thing is that the marks have very straight edges and right angles, making them so obvious. 

Does anyone think that neastsfoot oil and then sun-tanning would even out the hide color? Maybe subsequent applications of oil on just the light areas to try and even it out?  I really like the sun-tan look that some of you have posted on this forum. I'd like the chair to look like a well-used saddle.

I don't feel that dying is an option for me, as it's such a big hide I'd have streaks. 

[fredk]

Try masking off the already darkened areas; allowing the lighter square to get light - that might bring it a bit darker towards that of the already darkened part

[Bodean]

How long did this take to happen?

Edited May 5, 2017 by Bodean
correction

[bikermutt07]

I think your best bet is to make two smaller items from this piece. And get a new piece for the chair.

Sometimes wasting time working around a problem is worse than starting over.

.02