According to AP 2210H & J ( Meteor 8/9) Pilots notes, the limits were : from sea level to 2000ft 515Knots; 2000 to 20000 M0.80 and above 20000 no limit. The T7 Notes (AP 2210G) show slightly lower limits. From memory, compressibility precluded excursions much past M0.80 as there would be wing drops and control could be lost till denser air was encountered. I do not think that anyone could get a Meatbox through M1.0 although I would like to be proved wrong.