Killkenny,
First off, "welcome" to the LWF. There are so many others on this forum much, much more schooled in the art of leatherworking, so this information I pass on is just how "I" do my holsters. Before I sew it up, I finish the inside of the holster with a 50/50 ratio mix of water and gum tragacanth. I brush it on going with the grain and let it dry. Thats all I do, unless I want to dye the inside. As far as "how much neatsfoot".....again, JMO...I put i fairly light coat on the "outside" after I dye it and the let it dry overnight. That put some oils back into the leather that the dyes take out. By the way, I use alcohol based dyes from Feibings or home-made vinegaroon (vinegar-black). Then I finish off the holster, with 2 light coats of a 50/50 ratio mix of water/Resolene to seal the thing up. When I first started out, I would try to rush things and wouldn't let the leather dry properly. Now when-ever I do a operation, (other than the final Resolene, that about 15 min. between coats) I let the leather sit overnight and the projects come out much nicer. Patience!!!!! A word of advice....don't try to make this all to difficult. Read all you can on the forum, use the search venue, ask ???????, and enjoy. Semper-fi MIke