you can see the 'embedded in scratches' bit here...

you can see the 'embedded in scratches' bit here...

{{!gwi}}

Hi,
That's curly maple (maybe curly birch) and the dark areas are old tear-out from the planing. Curly wood has uncontrolled tearout because you can only (rotary) plane in one direction, and the curly grain runs in two directions, so it will tear.
Long story short, a long time ago, the woodwork was stained dark mahogany, and the stain is trapped in the open grain and tear-outs. Good news, wood bleach (peroxide type with part A and part B) will take out the dark color.
Casey

Thanks Casey, you're a fount of knowledge! I'm getting everything else off with DNA - - could it just be old shellac in the grain area? Also, can I scrub those tear-out areas with a brass brush (and stripper/DNA)? Or do I risk doing more damage?

This post was edited by sqsemi on Thu, Jul 17, 14 at 7:02

A good first try is to use the easiest and mildest approach, so, yes, it's fine to try stripper or alcohol and a little scrub brush.
If you restained it dark, then the dark areas would blend right in.
Casey

That looks like heat gun burn from a left-handed paint stripper.