1 hr. on the dash to throttle assembly connection.

Holes drilled (drill bit no larger than the holes in the assembly of course).

You can't install a rivnut over the leather so it needs to come off where those go.  The leather doesn't come off easily, so cutting underneath is required.  Takes patience...

Leather off and M4 rivnuts installed after I reamed the holes with my M4-sized chucking reamer (actually started with smaller reamer bits to work my way up to the M4 bit because it's pretty big).

Well, that wasn't too hard. :-)