Great info, Eric! My technique is very similar except I use only Burnt Umber oil; I vary the wood color by changing the base coat. All my graining is done with a good quality cotton swab.
Last year, I did a demo for my local club. I put together this sheet of styrene for that. Ten different base colors, some ModelMaster enamel, some Tamiya acrylics.
From left to right, base color, oil applied, wiped with swab, Tamiya clear orange overcoat.