If you read some of the old books, particularly Fred Ness' "Practical Dope for the Big Bores", you get the impression that there were Sedgleys and then there were Sedgleys.  Some were just put together from surplus parts.  Others were extensively modified, apparently including re-heat treating the actions.  I have read that the latter are sometimes found with a Sedgley serial number instead of the one applied by Springfield Armory.  Those are mostly found with low numbered 03s, but apparently Sedgley did the same things to Krags.