I like the 1" tubes, hard to find a new one with larger tubes. The petcock may be a little low. Prices looks about right with shipping - just under $300! Not sure about the hoses: - Upper hose connection is 1-9/16, lower is 1-5/8. I thought they were supposed to be 1 1/2 top and bottom?
Looks good, and yes, the hose connections should be 1 1/2". You should be able to stretch the hoses on, so that should not be a problem. Yes, the petcock can hit the core support if it is too low. Worst case scenario is you notch it. See if you can call them. If they make the radiators themselves, maybe they can alter the inlet and outlet sizes and move the petcock.