David Weaver
I have a couple of older chisels, but not sure that I have any old enough to have been pre-bolster (at least none that have been left alone).

I recall george mentioning that at CW, they were experimenting for ways to add a bolster. It would seem to me that the least difficult way to do it would be with wrought iron chisels and a wrought iron bead/wire laid around the tang as you mention. It'd would be lovely to hammer it in integrally by thinning the tang on both sides of the bolster, but I see that leaving more filing. Perhaps on an anvil with a really sharp corner you could do something like that accurately.

I have no concept of what it's like to forge super hot when metal moves easily, nor to forge something that moves more easily like iron. I"m hammering the tool steel around critical and in terms of how much it moves, very little. If I overheated the steel near the tang to try to forge weld something on, it probably wouldn't be a big deal, but forging the bolster to shape at this point and shrinking it on is a little easier to be sure that I won't have a bad weld (I don't think high carbon steel forge welds that well to mild steel).

I leave the tips a bit blunt just because I'm not filing them all the way tapered out. I'm starting with the file tang which is a bit thin for my taste, so I can't (without shifting further down the file) make the tang taller and steeper and squared to a point. It's mostly the shape of the tang that came with the file perhaps hammered in from the sides a little bit to build up the height a little - but toward the very end it's just filed off.

Am i correct that most of your chisels are laminated, or are the ones that taper that drastically all cast steel?