And what is then an equivalent focal length for 124.5 degrees?

One way of looking at it is to see what lens produces 124.5 degrees of FOV on 24x36mm sensor, which would give us

sqrt(24**2+36**2)/2 * tan(rad(90-(124.5/2))) = 11.38 mm

but that is, of couse, not entirely correct... The thing is that you'd have to crop the image from top and bottom to produce the same aspect ratio that "virtual 60x24" frame gives us... So we have to further shrink the short side of the frame to account for that "virtual extension" that shift gives us. So we get

sqrt((24*36/60)**2+36**2)/2 * tan(rad(90-(124.5/2))) = 10.2 mm

All in all, it means that you can produce similarly-looking frame by snapping 10mm hyper-wide Voigtlander and then cropping the image to 60:24 == 5:2 aspect ratio.

And the same calculation for the 24 t/s, please?

By how many millimeters it shifts?