Rick, I tried to PM you but you box is full.
I have a couple 28" radiators I picked up from a friend that parted out a couple imperials as best I remember. One is a 73-440 28" 3673958.
The other is a 72 440 28" 3574601. I also have a 28" shroud that was on one of them. I would recommend taking both to radiator shop to be checked out, as I know nothing about them. He just parted a couple cars years ago and had them in his shop and I bought what he had left.
If you need or could use any of the stuff let me know and I can try to bring it to the nationals as I come.
Matt