I was very happy to find the replacement part at 'AppliancePartsPros.com'. They were much less expensive than ordering through GE. The website was easy to use, had all of the information I needed to identify the part, and, shipment was ahead of schedule.
The repair took about 1/2 hour in total, which included disconnecting the dryer, the back panel to the control panel (6 screws), and, replacing the timer. The actual timer replacement was an easy process. I took a digital picture of the wire arrangement for 'back up', then attached the old wires to the new timer 'wire for wire', then reassembled the control panel.
One 'tip' that made it easier, was sliding the control panel front off off the dryer base. (It has tabs at the bottom that lock into the base). With the panel on top of the dryer, it made for easier access to the timer wiring.
In my opinion, this is a very poorly designed OEM part. The plastic shaft bound up on the old one, and, eventually became impossible to turn with a pair of pliers. If I knew the repair was so easy, I would have replaced it a lot sooner.
Putting the new knob on was a breeze. I'm glad to see the replacement part has a metal band around the end to provide additional support.