No doubt he would have been granted an exemption back then but the quality of the league wasn't that great either.
It's pretty hard to put into any context.
His age 15 season in 64 is what is really remarkable as the OHA had shrunk to 8 teams and Orr's 72 points only put him 7 behind the 10th place finisher. And that top 10 is a pretty good list too.
http://www.hockeydb.com/ihdb/stats/t...4&leaguenm=OHA
we all know what happened though.