I'd like to point out that what I do in my tutorial is to let the antique stain sit at least overnight and dry thoroughly, then I go over it with the moist cloth. This procedure smears it out rather than takes it off so you should not use the normal technique where you wipe all off. I have no idea how this technique will work with other antiques. What I used in the tutorial was Fiebing pro oil red dye first and after that was thoroughly dried I applied a rich layer oh Tandys old mahogany. It sits quite much on top of the leather when I'm done wich is also why I applied a rich coat of Fiebings leathersheene. I think the leather sheene can be buffed to a more natural shine than other acrylics I've tried and seem to withstand water quite a bit if leather gets wet.
I've never tried Fiebings stains so I can't have an opinion about that.
How about adding red dye to the stain to avoid the pinkish?? My guess is that black will turn it just darker pinkish but that is only a guess. Try with some scraps to see how it will turn out and REMEMBER write down the mixtures when you try. I use one of those lab thingies that you suck up the dye with and it is measured in milliliters wich is very good when you need to write it down.
Sidenote: adding red dye to Tandys old mahogany makes it sort of jelly like consistency, maybe stuff like that happens with Fiebings oxblood too??
Tom