Not having owned anything newer than a T4 17, so I have to ask, is that spur gear assembly in backwards? On the 17, the screw heads would be on the other side.....the side for the short belt. Just asking

You are correct. It was also caught, about 4 hours earlier, by someone in the XRAY thread. As I told him, the image in the manual is small enough that it can sometimes be difficult to tell. In cases like that, I usually use a flashlight. I thought I was correct, so didn't grab the flashlight...and I wasn't. It's corrected now - proceeding to step 3.