Use some Sno-Seal on the leather, it will seal the leather from weather and oils and prevent the from getting into the tang and rusting it. It will also slightly darken that leather and give it a shine. It restores all leather products and sheaths. Sno-Seal will also plump up old dried out and cracked original spacers to almost new. I recommend this product for all leather handled knives and sheaths. Just apply it with a lint free rag/bath towel and use a blow drier on medium-high to melt the product and work it into the leather. It may take a few applications to swell up old leather. Just FYI. I used Sno-Seal on an old Cattaraugus Quartermaster 225Q and it worked wonders. You did a great job rehandling this. :thumbup::thumbup:
Also - if you want to take those sander lines out of the blade you can use 1000grit wet/dry with a lubricating oil (honing oil etc..) and place the paper on something completely flat, and holding the handle, rub the blade carefully across the paper backward and forward (Not like you are sharpening). Be very careful to keep the knife blade FLUSH to the paper, so you don't create imperfections in the blade or ruin any lines. Then sand to 1500-2000 grit all the way up to 4000 grit for mirror finish. 2000 grit and up should be done with some Flitz metal polish. It will give a satin mirror finish on the blade. You can get 1000grit wet/dry at about all big box hardware stores. 2000+ you may need to buy online. To remove patina use a brass gun cleaning brush - it is abrasive enough to remove oxidation from the blade, but gentle enough not to leave scratches in the steel. Brass is softer than the steel but harder than black oxides. Keep in mind if your blade is pitted you may need to use a product called Loctite naval jelly with medium steel wool as an abrasive (an acidic product that softens up hardened black oxides from rust) to remove the oxidation from the blade. If you do this, rinse the blade in K1 Kerosene or gun oil such as Rem-Oil (both are petroleum based, and work as good penetrants **Keep in mind that petroleum based products will darken leather, so don't get it on leather**) to make sure you remove all traces of the Naval Jelly from the metal. It is caustic. Naval Jelly will remove even the hardened black oxides from "pits" in steel. If you do this, you can make your knife look pristine new. It looks great just like it is, but just for your information. I have done a lot of restorations on knives, and this may save you some hassle and headaches. :thumbup: