Hi David
looks like you are making progress on the buick, thanks for posting the progress!
A word of caution...... I see the jackstand is under the frame not the axle. I was taught that the vehicle should be supported by the suspension and on a close to level surface when removing and installing quarter panels.
The frames flex so if you weld the panel on when it is flexed, it may buckle when the car is put back down on its wheels
steve