Checked igniter with an ohmmeter and found it to be functioning. Did the same with the gas valve coils according to the Appliance Pros web site and they too appeared to be functioning. Based upon the repair video, the ohms test could be inconclusive. I tested the remaining parts and they seemed to be functioning.
The most likely source of the problem appeared to be the coils. I replaced them and the twenty some year old dryer works fine.