Origin of saying 'hold this 'bout an hour'

Factual Questions
1

My brother used to say that to his younger sibling when I’d be looking over his shoulder as he worked on a car, or whatever. He’d hand me something, and say, “Hold this 'bout an hour.”

I said it to my grandson today while helping him get his sneakers on. I untied and loosened the strings, and handed him one, “hold this 'bout an hour”. He giggled, and a lady who was passing by said, “My Dad used to say that to me, too. Wonder where it came from?”

2

Partial answer: “an hour” is an expression meaning “the right amount of time”.
its a very old literary short cut … of course the amount of time is unknown, variable…

Eg Shakespeare said “hour” when he didn’t mean anything like “exactly 3600 seconds”.
"Life’s but a walking shadow, a poor player,
That struts and frets his hour upon the stage,
And then is heard no more. It is a tale
Told by an idiot, full of sound and fury,
Signifying nothing.”
― William Shakespeare, Macbeth

3

Have you heard anyone else use the expression?

4

Western Pennsylvania, never heard the expression until today.

5

Ohio, SoCal, New England, and a Linguist–never heard it.

6

I think mechanic’s argot is fascinating. I wrote a paper about it in college after spending a summer as a mechanic helper/gopher/truck washer.

One old hand, working for me years later, had a favorite line he would use when trying to line up bolt holes or somesuch…“Hand me a pencil so I can draw this together”.

And, of course, the common one about needing to put a ‘little hair around it’ to get things to line up properly.

7

or, the farmer with the magneto-powered spark plug wire who would disconnect it from the distributor, and have a youngster ‘hold this for me’ while he cranked the engine over. No one ever gets knocked on their rear more than once with that one. You remember.

8

Or, they’d get you to stick your head over the engine to watch for a ‘leak’, then blow the horn…

9

One guy, who serviced our tractors and service trucks, always, the last thing he did before taking the keys back to the key-board, would be to turn the radio up to the highest volume on a top-40 station.