At this age, many elderly appreciate help around the house.
He is doing outdoor things/his farm.
BUT, what about hiring a Window Cleaner?
Or you guys go over there to clean the interior for him?
Or, fix anything that needs fixing?
Or even just cleaning out his gutters? Elderly, can fall from high places/on a ladder and don't have good balance. For example.
I know someone, who is a part of a community group. And what they do, is simply help fix or clean, any Elderly person's home. Many of them are Widows as well. And they really cannot do EVERYTHING like they used to. They are older. Even if your Grandpa does things outdoors or for his farm, I am sure there are MANY things, per his home, that could be fixed or cleaned. My friend says, that the Elderly people they help, JUST LOVE that they do this. And they just do it for free as a community service. MANY elderly, simply cannot do nor keep up, with their home's upkeep. One elderly person they helped for example, had a broken front door. And it was not fixed because the woman could not do it nor hire anyone to do it. Not even her family, would help. It was just, sad. And she was afraid that an intruder would come in or rob her home.
At this age, they really would enjoy that kind of service or help... or even some good meals. Especially those that are Widows.
Or get him necessities. That he wouldn't necessarily buy, himself or due to budget. Many Elderly, have budget constraints.
But as for objects as a gift: what about a nice Lazy Boy recliner????