I agree the darn thing looks great!
On the panhard bar weld, what I am curious about is it was only 3/16th or so short, so you welded up that gap using the nails, how did you arrive at that distance? Did you measure from the rear housing flanges over to the frame or center line centering the rear axle housing in the frame and this is how you have determined the length of the panhard bar was off that 3/16th inch?
Because is that is the case and you did this without weight of the body on the frame as Randy pointed out the panhard bar is going to effectively "lengthen" when the additional weight pushes the frame down and the panhard bar goes up in the arc. If you determined that length at this point, when the additional weight is put on the frame that bar is going to be too long, probably just about exactly what you have lengthened it!
Now, that tiny amount isn't much to worry about it, but as Randy also pointed out the weld may not be that great after grinding so maybe you want to re-think that measurement? I nice butt weld with a beveled edge may be a better choice.