So I have this old Dozier kit knife that it looks like someone hammered the wrong size pin though and cracked the tang, its actually broken all the way off and just held on by the scales. I was thinking of putting some new scales on the knife, Is there a way this can be welded back together or should I just leave well enough alone?

Since you are going to put new scales on that blade I would have it TIG welded, a TIG weld would not introduce enough heat so the temper of the blade will not be affected. The weld bead will be small and easy to clean up by drawfiling.

I would just leave it as is.

Double post

Maybe try to clean it, and shoot some epoxy in.

If you are definitely going to rescale, I would get it tigged.

Fill the crack with super glue and use it till (if) it breaks.
When (if) it breaks do the weld procedure noted above

grind on it and add another pin to make it a 3 finger.......

If you decide to have it repaired by welding, you need a welder who knows how to weld tool steel or it will crack again. Welding tool steels requires the blade be pre-heated and a proper filler rod is used as well as allowing a slow cool down to keep the weld affected zone from hardening. If somebody just runs a bead down the crack, you'll have nice hard spot where the crack was as well as stresses in the heat affected zone and a hole in the middle of the stress riser.

If rescaled.....silver braze it. Very strong. Everything clean. Relieve a LITTLE inside so there is room for the silver on the inside. Clamp it down and there should be next to no witness of the break.

Great idea there.