Bristow....Bristows.....Bristow's.....whats in a name. So long as the word has commonality of definition effective communication can take place.
It seems we all know what was meant by "Bristows".
That being said, I suggest Bristow's can only refer to Bristow during the ownership by Mr. Bristow as one has suggested previously.
Now how can we argue the statement...."I flew for Bristow". Does that refer to the company when Bristow owned Bristow or would that have to be "Bristow's" to be correct?