Lovin' this thread! Here's a few favorite expressions from my late-grandfather:
Meat that's hard to chew is "tougher than a boiled owl".
Good friends are "closer than bark to a tree".
A very homely person is "a two-bagger" (in case one blows off)
Another homely person "would make a freight train take a dirt road".
A clueless person "hasn't got both oars in the water".
Another clueless person "doesn't know if it's Tuesday or August".
On a good day, he'd say "If I was any better, I couldn't stand it."
Crooked carpentry was built by "a guy who used a banana for a straight edge".
Someone who complains a lot "he barked until he was hoarse".
All of these things add color to a conversation, and Grampie could tell a story / yarn better than anyone I've ever known.