Char from old barrel

[The Baker]

I really like the idea of Badmotivator's barrels but couldn't get one because of the freight cost, largely (to a different country).
I am working on the idea of an oak cover on a coffee jar (which has a nice flat rim at the top, not screw top).

Sorta kicking this around...

Anyway, today I got a barrel staff from the local winemaker. Five feet two inches (157.5 cm) long
and about five to six inches (12.7 to 15.24 cm) wide,
varying of course.
He cut it in half with a chainsaw so it fitted in the boot of my car.
An inch and a half (3.81 cm) thick of which three eighths (.9525 cm) is heavy char.
These staves have been sitting in the weather for probably years.

I expect to cut it into say (just under?) five inch (12.7 cm) width and around six inch (15.24 cm) or twelve inch (30.48 cm)
lengths (for one jar or for two jars side-by-side).

I have some thickness of wood to play with but will need it to make good levelish pieces.

And I speculate a bit here, not being a woodworker:
After cutting the wood into these short lengths my friend the kitchen man could then cut off the char side roughly, and roughly square with say a band saw.
Leaving me the bits to play with...

Then he could straighten the sides with a thicknesser and straighten up the curve of the wood a bit.
Doesn't need to be truly straight except for the centre four and a half inches (11.43 cm)
or nine inches (22.86 cm) (actually a fair bit more because of the gap between the jars)
at the top of the curve
(which I will place downward touching the spirit) for the one or the two jars.

So any bits of oak left from this operation I will keep and use when aging spirit in glass.
Do you think the black, weathered charcoal would be good for that?
As an experiment I would use say an oak nugget and a lump of the rough charcoal together...

Geoff