I have used US Radiator for years, but sadly the last couple we received were pretty bad dimensionally...not symetrical top to bottom, side to side....just quality control issues ( or lack of?)

I've never heard anything negative about Walker other than regular minor issues you would have with anyone's stuff. I'd put my money on a Walker at this point. A lot of people recommed Brassworks, but I have no experience with them, so I can't help with that.