The inlet on my '37 was very rough also but sealed just fine. On these old radiators, the inlet and outlets are cast iron soldered into the brass tanks. It doesn't take much to get them to leak at the fittings so go slow when handling them.
If you are good with a torch and solder, its not to bad to repair. I was getting pretty good at fixing mine till I switched to a all aluminum radiator a couple of years back. I could not keep the top tank seam to stay sealed, once a year I would pull it for a touch up. I believe the top tank brass was getting thin and the flexing from heat cycles would crack it where it soldered on.
Joe
