If it has a speed it has a rest frame. The concept of a rest frame was part of physics 10+ years before the speed of light was even derived as a constant by Maxwell. And, by Maxwell. The statement that light does not have a rest frame is revisionist. Just say'n.
That said, of course you are right that at light speed nothing can be measured, as a practical matter, because that inevitably requires mass. Pretty sure it took Einstein to make this distinction. Maxwell's original writings really are a blast. Like Einstein's.