Some of these timers, like this one, must have been a real bugger to install over the rotor!
Dale, I forgot to post the special key that holds the rotor on the camshaft. With the rotor installed in the timer, off the car, you then place the key in the rotor and slip it onto the camshaft.
I have a new old stock one of those but without the little key. It looks like a very good design, probably better than most. I wondered how you were supposed to put the rotor in. The little key solves the question.
It looks like the timer is made from the same type of bakelite, phonilic or whatever it is that the New Days were made from.