Simplest way it to wet all the washers and put them on a bolt with nuts and washers on both ends.Tighten down good and tight and let dry for a couple of days.Take of and re-install on the knife tang in the same order,putting epoxy (slow cure) between each washer.Tighten down the pommel nut and let cure for 24 hours.Sand to shape on the belt grinder,going slow.Smooth up with a 400 grit belt.apply a good sealer and buff.Sealers vary as much as makers do.Super glue,Atom Wax (my favorite),tung oil,carnuba,linseed oil,etc.
A trick I use is to make a mandrel to work the handle on.It is a 1/2" bolt which I have flattened to a 1/4" thickness.I assemble the wet washers on it,dry them,re-assemble again with the glue,and when the glue is set but not cured (about 2 hours with the slow set) I unbolt the nuts, place one end loosely in the vise, and tap the bolt out with a mallet.Scrape the extra epoxy off the bolt and re-insert and re-tighten.After the epoxy cures,you can then shape and finish the handle on this mandrel to its near final dimensions before putting it on the knife tang. You avoid damaging the knife while doing all the shaping.You can slip the handle off and on the knife while shaping to test fit it.You can even put your bolster on the mandrel with the washers and grind them at the same time.