Looks like Grotesque One Three and Calibri, but I can't be 100% sure. Anybody know?

Possibly, although I have seen other images where the R doesn't have that modification. It does look like an already-existing font that has been modified, much like the current Doctor Who logo does with the Gotham font.

What's the font in the logo for the British conglomerate Thorn EMI (who's film division produced the original Highlander)? I only ask because the font in this image and the one in the SVG files on Wikipedia and Logopedia are different.