Thanks for solving that mystery. Looking in the Haynes manual we have, I
see the section on checking the cruise control mentions a brake switch,
which of course would be for an automatic transmission. It would have been
easy enough to label that switch on the clutch pedal diagram!
I'm not sure my friend ever uses the cruise control. He's an old school
european plus a bassist. In the early 70's, he just walked away from the
Czech symphony when they were on tour, eventually ending up in New Orleans,
and he retains a lot of his home-country ways.