Yep, my grandpa had a tree in his back yard in SoCal when I was a kid in the 60s. It was a good 30 feet high, I figure he must have planted it in the 30s along with different oranges, lemons, grapefruit, etc.
How lucky you were, to have a grandpa who had such a wonderful variety trees.
We have four avocado trees in our back yard. They all produce and we are loaded with guacamole.
We had an aunt, who lived in SoCal, who had a YUGE avocado tree, in her backyard.
It produced big, tasty avocados...and, it was amazing to be able to just walk out the door, pick a few, and come in and make a fresh bowl of guacamole, in a matter of minutes.