Duane Eddy - The Climb download song

Great cover of this Coaster's number. Anita Kerr's bass singer is awesome. And these dancers are way cool. Yes, Jim Horn on tenor and other RCA Studio B "A Team" session players as listed.

Yet, Harold Bradley is credited as tic-tac-ing with a Dano 6-string bass. Are they both using the same kind of Dano?

What you're hearing is a Danelectro six-string bass. No 6120 could be tuned that low without horrifying intonation issues.

The French people tiring themselves out are doing the Madison, a line dance that originated in the USA but which attained much more popularity in other countries.

More than likely. Dano's differed in appearance only, with their construction, pickups, etc. all identical. Harold evidently commissioned the first one. The timbres!

Anna Karina with Claude Brasseur, and Sami Frey in the famous dance scene in the French film "Bande à Part" ("Band of Outsiders" in North America),

I heartily disagree back. I gig and record with baritones, bass VI, and several low and/or open tuned standard guitars and I know the differences in timbre between each. Glad you're getting the results you want, though.

I heartily disagree. Duane could just tune his guitar DGCFAD - it is only one tone lower than usual - and more than make up for any intonation issue using heavier strings. I maintain he did so on this tune, but also in "The new Hully Gully", "Wild Watusi", "Blowing up a storm" and a few more tracks. I myself usually play my Guild AA in "D" tuning, using D'Addario "light baritone" strings - and the outcome is identical!.