I get a replacement set for every new UCS and large scale Technic set I buy and have for years. I always offer to pay for them and they never take any money. I dont know if I am just lucky but thats been my experiance...

I think I might contact TLG and give it a try, they can only say 'no' eh. Thought I might wash the stickers off the parts that are peeling and leave them bare, but that would drive my ocd insane!

If anybody happens to have a larger sized image, I could give a go at turning it into a vector in Illustrator. Doesn't really matter what the resolution is as once it is turned from a raster to a vector image, it can be scaled to any size without loss of quality. The only issue is photographic components. The basic solid color stickers are quite easy to trace in illustrator, but photographs are a bit tough to handle due to the gradual color transitions.

Super late to the party here, but I'm having the same problem with set 10026.  All the stickers are old and peeling and cracked.  However, some of them are still in good enough condition that I think I could take a high quality photo of them, and maybe fix them up in a photo-editing program.  The only thing I'd need then is the exact dimensions of the stickers (difficult, given the odd shapes of some of them), and I could scale them appropriately, then create an image of the sticker sheet on my own.  Unfortunately I don't have access to the tools to measure them that precisely.  Can anyone help with that?

I have a decently high quality image of the display plaque already, but personally I care more about the stickers on the model itself. 

It may be easier to go to Ebay or sellers websites and get a set of replacement stickers - I've used a couple of shops a number of times (e.g. Zacparis on ebay and ultimatecollectorstickers direct) either for replacements or when I have bricklinked a UCS or larger old set and the second hand prices have been crazy - quality is usually top  notch.