Hmm, yes folks I am totally red-faced with embarrassment. The reason Argyll wasn't working for me is because I installed the v60 patch over the v70 installation. Or at least I think I did.
Anyway, a fresh binary installation and everything seems to be working exactly right. I was able to import my last Spyder calibration performed under windows, a couple of months ago:
dispwin -v /usr/local/argyll/Spyderlastwin.icm And check "existing" (newly imported) calibration: sudo /usr/local/argyll/bin/dispcal -v -r -y c resulting in: Current calibration response: Black level = 1.07 cd/m^2 White level = 138.11 cd/m^2 Aprox. gamma = 1.95 Contrast ratio = 129:1 White chromaticity coordinates 0.3114, 0.3281 White Correlated Color Temperature = 6584K, DE to locus = 4.9 White Correlated Daylight Temperature = 6584K, DE to locus = 0.3 White Visual Color Temperature = 6405K, DE to locus = 4.7 White Visual Daylight Temperature = 6573K, DE to locus = 0.3 The instrument can be removed from the screen.Now comes the fun part - figuring out what all this means, how to do a "real" calibration, and how to actually put it to good use when photo-editing.
Thanks so much very much to Lars and Ross and Edmund for responding to my plea for help.
Elle