After more testing I found the flame sensor was bad as was the ignitor. This particular version of ignitor was the tubular type but I was able to replace it with a flat blade type. After more delicate work I was able to make things fit and got it to fire up OK. These older units are made to last but sometimes it is a PITA to make things fit and work. I am going to replace the gas valve solenoids also before I close things up.