I like to use alkanet root infusion to darken stockwood and impart that marvellous red tinge suggestive of old oil finish.
Might not give the typical brown colour of a Type B, better for the Type A perhaps.
The added advantage of alkanet is that it enhances the contrast of the grain, rather than muddying the figure like conventional stains.
I infuse the alkanet chips in a 50:50 mix of gum turpentine and linseed oil, but linseed oil alone is usually recommended for those with more patience than me!
Also I have convinced myself that the thinner infusion takes the red colour deeper into the wood.
Mineral turps is probably just as good as gum turpentine, but doesn't smell quite so business-like!