This might be US-specific ageism issue. Did you consider moving to Europe? I would especially recommend eastern Europe, people value experience and abilities ab

This might be US-specific ageism issue. Did you consider moving to Europe? I would especially recommend eastern Europe, people value experience and abilities above everything here. One thing that is missing from your CV is experience with linux system/embedded s/w, you would rarely have any device nowadays that does not include or interface linux in some way.