A couple of random thoughts...
According to AI, the death of someone who died in Padstow in 1954 would have been registered in Bodmin (correct it if it's wrong, I'm in Brazil, so no idea!).
If his death was registered in Liskeard maybe he has been buried or cremated somewhere nearby or anywhere in that direction.
I have noticed that the newspaper announcements of his death were from all over the UK bar Cornwall. Cornish papers have published notices regarding his estate but not his death. Does that mean something?