I'll try that tomorrow. I could also put the winter wheels/tires on there for a test drive.
The knuckle does not look bad at all. It cleaned up nice. I think the inside surface is nothing more than casting marks. Without seeing it in person it's hard to tell.
I would recommend putting it up and stands or a lift and inspect all wearable suspension/chassis components. Also motor and transmission mounts. If everything checks out drive it up on ramps and have someone rock steering wheel and push hard on each corner of the car in all directions. Sorry I can't be of more help but vibration issues can be really hard to find.
The main thing is removing weight off of the vehicle then full weight of vehicle when checking.
I have AAA here in CA and it's the best!! You can't beat a good roadside service plan.