Flanders Fields Museum seeks owner of letter from Great War -- https://www.brusselstimes.com/belgium/1188271/flanders-fields-museum-seeks-owner-of-letter-from-great-war
Here someone found more information: https://www.reddit.com/r/CasualUK/comments/1ewbusc/did_you_lose_your_centuryold_letter_at_tyne_cot/
On Familysearch: https://www.familysearch.org/search/linker?ark=/ark:/61903/1:1:QVVN-PF67&id=G4V5-NLP&hinting=/tree/person/details/
His son Ernest Edward Webb died in Devon in 1977. Maybe someone can help in this?