Hi All,
I've got it at last!!!!!!!!!!
Decided to have another attempt at John's death today and once again combed the census and death records in Scotland, given that it was the last sighting I have of him.
After much mucking around, I have finally found John's death. He died in hospital in Leith in 1936 and there is no doubt of it being him due to the naming of his wife Barbara.
His usual address was given as Bathgate but the informant at his death was his brother William (of Leith).
So, a problem solved at last. Thanks to everyone who contributed with ideas, much appreciated.
Regards Eliza.