OneGuyFromBarlick

I think Tom has remembered it. No Peter, it's genuine ebony.

I thought ebonite because Plaques was making reference to sparks. You can get an electric spark from ebonite but not from ebony.

Big clue..... Very useful in the office....

Jewellers pen ?

Is it a sort of rolling ruler / straight edge - though I can't imagine how to keep it still enough in use.

David is right, an ebony ruler. They made them round mainly for laying out accounts. If you roll down the page you can easily make parallel rulings....
Next one anyone?

Where is this?

Belgium?

Getting there Kev.... But where?

Menin Gate, Ypres?

Yes Kev, well done.
Next one?

What is it?

Don’t know but I keep thinking that I can see a Gumnut.

Something to do with the Cheshire Regiment?

Hat badge ??

As Wendy says, Cheshire Regiment. Collar badge?

Wendy and Kev have it. Collar Dog from me days in the 22nd of Foot, The Cheshire Regiment.
Next one?

What is it?

No takers?

Is it for lime ??

You are so near Tom! It's used to prepare one of the key ingredients used in the production of fine pottery. (You've seen it before.... )

Grinding `china stone' which is added to pottery clay to give it the porcelain look? Wikipedia

Grinding bones?

Wendy has got it! To make it a perfect answer she could have added 'Calcined'. These grinding mills are at Shirley's Bone and Flint Mill where both these ingredients were first roasted in a kiln and then ground into a slurry . It's part of the Etruria Industrial Museum and open to public view.
Next one?

Shirley's Bone and Flint Mill started by using bone and flint to make a porcelain-like pottery ware but later used china stone (also known as Cornish stone*) when it was discovered that it gave a product identical to porcelain.
(*A partly kaolinised granite free of the original black mica and thus able to give a pure white, speck free product.)