Ron Nasty said
Again, there would be also be problems with that as their records were not issued in a uniform way worldwide. Virtually every country in the world has records that are unique to them. The level playing field is lost, without even taking into account that countries compile their charts differently. Some based solely on sales, others based on a combination of sales and radio play.
Good point. However, I found some information on Beatles worldwide record sales on Beatles Radio http://www.beatlesradio.com/members/RecordSales.html. Not sure where they got the information from, but its a start.