Goodmorning Les!
I have found some info on John Darley.
Death recorded July/August/Sept/ quarter 1956 at Howden.
He was 74, as you stated. The reference number is Volume 2a
page 96
The only difference is is middle initial is K. I would not worry unduly about this, I have found so many mistakes in census and
other transcriptions.
I believe you can now order certificates, from abroad on a website set up by the GRO
WWW.gro.gov.uk
I hope this is of some use
Kind regards
JeannieR