It's the first 30' exclusive of level tip. This was put into the specs, I imagine, because back in 1962 it was common for manufacturers to leave a substantial length of level tip so that users could trim it back to suit their own casting style. Some English silk lines had as much as 12' of level tip.

So, suspend the level tip and don't weigh it. Don't worry about weighing only 30' of line; that length was a rational choice in that most stream fishermen need no more than 30' of line beyond the rod tip. With a 9' leader, plus 30' of line, plus 9' of rod, less 2' for catenary, you are reaching a rise 46' away. JMO