Cleaning Older Pelts?

[Lunalura]

I just wanted to see if I could get any advice on the cleaning / brightening of older pelts. I recently got a completely gorgeous Silver Fox, but didn't realise his age when I bought him. I have a feeling he is vintage (leather is yellowing too and has that noticeable smell), but it's still strong and in good nick.

I know I can't fix the leather tinge, but he has alot of yellowing through his coat aswell, especially on his tail tip. He has alot of silver tipping on his back too, that should usually be, well, silver, but all of that has a slighty yellow tinge now too. I was wondering if there was any way to help this, i'm not sure if it's because of actual staining or perhaps it's just dirt buildup over the years? His coat also doesn't feel as soft/silky as it should, almost 'greasy' is the best way I can describe it.

Any help would fantastic - thank you in advance!

[BTBczyk]

I used a bissell cleaner on the last deer mount that I had to clean and it did a good job it took out allot of the dirt  I considered bleaching the white and decided it would make it look freakish so I left it the customer was happy