Much like the Sanhedrin and Pharisees would we recognize the 'divinity' in our midst or would it come from outside the recognisable pedigree/lineage?
Given more people are alive on the planet today that have ever walked the earth previously (forget how the quote goes). And today the average living age is up, as is nutrition and education.
Thus its a fair bet there are probably at least 10 O'Sensei's getting around today.
From beyond the circles of aiki I'd be tempted to start with a Systema boy or two, add a Gracie or two, a couple of MMA guys, slip in a footballer basketballer and maybe Tiger for good measure too