Excellent thread !
My grandfather (God rest) .. "Measure twice, cut once."
"So blunt you could slide bare-assed to Bradwell and back on it." (We lived in Bradwell)
"If it's not sharp, it's just a piece of metal." (This on the day he taught me to sharpen a tool properly. Now used as my sig line on most forums)
"There's no such thing as a 5 minute job."
Others...
(She's got a face) Like a bulldog sucking a wasp.
If brains was dynamite he wouldn't have enough to part his hair.
Not the shiniest pebble on the beach.
About as bright as the TocH lamp (TocH was local charity who's symbol was a big oil lamp, Ali-Baba style, with a tiny little flame on it)
He's got shit for brains and so little of that it don't smell.
If it went BANG and bits fell off, start saving up for a new one.
About as bent as a nine bob note. (Pre-decimal currency in the UK had a ten "bob" (Shilling) note)
Clean as a whistle.
Right as ninepence.
About as happy as snow in harvest.
I'd rather be a live chicken than a cooked goose.
(Me, on being told to do something wholly stupid by an RSM with the words "Get on with it! It's character building!) "I've got quite enough character already thank you!" (We never did see eye-to-eye after that. I wonder why! )
.. and I can't believe I'm the first to suggest...
If it ain't broke, dont "fix" it !