That may not be him though, what else do you know about him?
There is a William McKEON with wife Isabella in Sunderland in the 1911 census free index, and a William McKEOWN with wife Mary Ellen in Middlesbrough in 1911 census
It might be worth buying some credits to see the full details of both
If you know more about him, to save your getting the wrong certificate, you can check for any known details eg age, occupation, widow's name, before buying the certificate, the GRO charges for this, (included in cert fee if correct), but Middlesbrough register office would do this free,
Barbara