Sam,
Make a stacked leather mandrel. I'll try and find mine for photos tonight, but will describe it for now. This is how I make most stacked leather handles, and will work for any knife.
Make a replica tang in mild steel with a good shoulder for the guard It does not need to be fancy, just a pretty close match for the sword tang in measurements. Leave a 2-3" extension as would take the pommel nut, and thread it for a nut, say 1/4-20. Leave enough "blade" section to hold onto while assembling the handle. About 6" is fine.Make a simple guard like a big washer with a slot. Make a similar round piece that fits the top of the tang where the handle will end.
Cut the leather into rectangles or squares (no need to make rounded) , and slot them so they fit the tang. Slide them on the actual sword tang as you cut the, to make sure they fit.The stack should be about 3/4" longer than the desired handle length.The fit does not need to be all that precise. The hole will be filled in the next steps.If you are making a punch, I would make three sizes, to fit the bottom, middle, and top of the tang.You can just cut them with an X-Acto blade,too. Do any dying now, and let fully dry before asesmbly.
Keeping the leather pieces in order, slide the stack onto a piece of wire or dowel. Set aside the sword.
Coat the two washers and the mandrel with some sort of epoxy release agent. You can dip them in melted wax, or coat them with several coats of car wax.This is to allow the mandrel to be removed once the handle is cured.
Mix up a batch of slow set epoxy in a plastic container wide enough to easily reach into.You want one hour minimum set time, longer is better. What works best is fiberglassing resin. It is thin and sets reasonably slow. I recommend System Three Clear Coat. Woodcraft Supply carries it. It can be thinned,too.
Whatever you use, mix enough to do the whole handle in one opperation.
Put on rubber gloves. You will need to have them.
Have a helper drop the leather pieces in the epoxy one at a time. You will dunk it in the epoxy, wipe off the excess, and slip it on the mandrel, sliding it down to the guard washer.While you do this the helper will drop in the next leather piece. This will go really fast once you get the rhythm going. Continue until all the leather is on the mandrel. Slip on the top metal washer, and thread on the nut.Hand tighten it. Wipe off the excess epoxy from the leather and the mandrel parts. Put the "Blade" part in a vise, and snug down the handle by tightening the nut. You don't need to go any tighter than necessary to compress the leather pieces snugly together. Wipe the exposed threads on the mandrel well with acetone, and give the threads a little spritz of WD-40 (this will make removal of the nut much easier later).
Check the epoxy pot regularly, and when it is set, but not cured (it should just have just stopped being tacky), take off the nut , and screw on a piece of threaded tubing about 1" long (1/4-20 coupling nut works perfect). This is just for the purposes of striking the end without damaging the threads, and nearly anything will work. I just like to have about 1/2" of the threads engaged. Loosen the vise and set the "guard" washer against the jaws, with the "blade" loosely between them. Strike the threaded end gently with a mallet. It usually comes loose easily. If needed, strike a little harder. You are not going to take it off, you just want to break any grip the epoxy might have. Once it has moved about 1/2", put the nut back on and tighten things back up. Set aside to cure for a couple days at 70-80F.
Once all is hardened, take off the mandrel and clean the mandrel with acetone. Put the handle back on the mandrel ( leave the metal washers off) and rough shape it on the belt grinder. Now, test the handle on the actual sword tang. If all is well, it should be a forced fit. If it is too snug, file the inside with a riffler file. Shorten the length to the exact fit desired. Put back on the mandrel for further shaping and sand to about 400-600 grit. Work in a protective and conditioning coat of bag balm ,or similar leather treatment, and let dry.Give it a buff with a soft cloth, and assemble the sword.
This make a very strong and grippy sword/knife handle.
Stacy
It's a pain in the butt just doing a knife handle...much less cutting out for a foot-long wood-supported tang. Yikes! 
