I appreciate the suggestions received from the previous thread about how to clean the 67-68 brushed aluminum dash fascia. I ended up trying virtually all of the suggested techniques on a spare set of fascia that I got as a swap meet, but wasn't really very satisfied. There was gunk deep in those little grooves that I could not reach with common cleaner and cleaning tools, plus I did not want to create a new pattern of brush marks or scratches.

It occurred to me this morning to try a dremel tool with a wire wheel, specifically Craftsman 3/4" Dia. "carbon steel brush." It is a flat brush that can make a fairly precise edge. (For the record, the same basic brush also comes in brass and copper.)

If it matters to anyone reading this, I carefully masked the fascia in order to avoid getting any chemicals on the painted part of the dash, or damaging the paint with the dremel. Importantly, the variable-speed dremel was turned to its lowest possible speed and the brush was applied very lightly and for very brief periods of less than a second. If the dremel was left too long, it created a polished spot. Also, I moved the dremel horizontally, along the grain of the brushed aluminum.

I got virtually all of the deep-seated gunk out. The deeper scratches and other "character marks" were reduced but still present (I was reluctant to get too aggressive). I then applied professional cleaner to e cloth and the fascia looked much cleaner/better, while still retaining the 'patina' that we seem to be increasingly interested in retaining.

I don't know whether anyone else benefits from this, but it usually seems that an idea shared with the community tends to get better as guys with more skill iterate the concept.