no signs of Alzheimers, dementia or mental health problems when he went missing.
So what on earth happened to him?
I assume they've checked his house for obvious signs of a break in or a struggle having occured.
I don't think it's likely he's had an accident, he was apparently seen that night so where would he be going at that time of day? If he'd gone to a shop and suffered a heart attack for example you wouldn't think his route was so remote that no one would have come across him.
I wonder if there is anything in his life he might want to run away from - Debt etc. But you'd think Police would likely be able to find that out. If he's done that I'd hope there is evidence to suggest it e.g. withdrawing quantites of cash in the lead up to going missing.