Neatsfoot oil can be bought at most shoe and saddle shops. However, be sure to get PURE neatsfoot oil. Most products sold are actually neatsfoot COMPOUND, which is FISH oil, with enough neatsfoot added to call it neatsfoot.
Neatsfoot will darken and soften the leather, so use it sparingly. When you apply it, the leather will turn very dark, then lighten some as it soaks in. Since this is what was used by the military, it will give the holster that "GI" look.
As a watchout: Many leather "repos" have a clear finish on them that will partially prevent the oil from penetrating. If so, apply a small amount on the back side of the leather, and allow plenty of time for it to penetrate. After a few hours, the oil will distribute it's self throughout the leather, and the color will even out.
thebeekeeper1:
A good product to restore dried out leather, is Lexol. They make a cleaner and regular Lexol treatmen. This will restore the flexability of leather, without darkening it, or making it too soft. SHAKE THE CAN WELL, and apply as per directions, until the leather feels right. Then let stand for 24 hours. If it's still dry, apply more.
The correct method of sharpening is to buy some yellow or red rouge from a knifemaker supplier, or a jewelers supply house. This should be bought in stick form. Red is really to fine for steel, but most old strops have red on one side and white rouge or Tripoli, on the other.
Rub the rouge into one side of the strop. Either lay the strop flat on a table, or hang it from a hook, and hold the other end.
Lay the blade flat on the leather, edge facing AWAY FROM YOU, lift the back side slightly, and pull the blade down the length of the leather toward you. Flip the blade over, and pull it back across the leather.
This is the opposite of sharpening on a stone, where you push the blade across the stone, edge first, as though trying to shave a slice of the stone off.
As a matter of interest: You can make nice strops by buying a 2 inch leather belt strip from Tandy leather, or any leather shop. Be sure to get a belt STRIP, not a semi-finished blank.
Oil the strip with neatsfoot, or Lexol, and coat BOTH sides with rouge. Use the rough side to "edge" the blade, and the smooth side to give it a high polish.
This will give any knife a scapel-like edge.