It's streaked and mottled and too dark already

[MorningStarL]

I've got the six knife sheaths done.  Started dying them last week and knocked over the bottle of Fiebing's Saddle Tan.  Had enough to do two and more was on the way.  

The two from the old bottle are streaky.  The dye went on or took unevenly.  There's mottled patches.  I've been trying to even it out, without much success, and they're already darker than I'd like them to be.  The knifemaker is cranky and giving me grief.  

I don't know what to do.  I've made a test patch with more of the dye, and I'm prepared to try sanding lightly with 600-grit (I saw that on here somewhere) and I've got some Barkeeper's Friend, but haven't tried that yet.  I told the knifemaker today I thought the options were (1) over-dye them black (which the client doesn't want), or (2) start over and make new ones (and he wants to get paid sooner than that).  

I'll take pictures tomorrow -- too dark now.  Thanks in advance.