OneGuyFromBarlick

No offers? It's a protective glass cover for something like a clock face but very heavy. Here's one for you and I admit that this is getting into the further regions of mystery objects.

Dave's still not got over the two lens that were paperweights. He said he used similar in enlargers when he was a photographers aprentice. Eileen

Flame/fire viewing ports for a boiler of some description.

Eileen, many uses for them but I know this bloke was heavily into telescopes. Dave is not necessarily wrong.
Pluggy, that's what I though of at first but no, they have a very specific use which is similar but not boilers.

I'd better put you out of your misery. It's an American 'Doorscope', a high class version of the normal peep-hole fitted in outside doors but with the advantage that it could be opened to allow speech or the passage of small items like mail. Try this easy one....

There's nothing there Stanley, except a red cross in a small box and the word "image".

Sorry about that....

Eyelets...
Or part of a 'popper', such as a stud on clothing, though you need 3 other bits and a tool if it were a clothing stud (used to use them a lot on kid's clothes when my son was small)
So I would say it is an eyelet such as can be attached to canvas etc.

Countersunk washers for brass wood-screws...

Sorry Maz, Young Jack has got it exactly right. Used on high class fastening especially when screws have to be frequently withdrawn for any reason. Now I'll have to rack my brains again!

All right, it's a cutting tool but there are one or two things about this that are special. Why is it black and so short for instance. Any ideas? I promise it's quite interesting.

There appears to be minimum top rake angle, a guess boring bar tip for cast iron cylinders in situ, why blakck ?, graphite

Mrs Tiz suggests it's black to better absorb or radiate heat.

That old fox Bodge has hit the money again! Quite right but the reason it's black is because it's very old and made out of cast high carbon steel bar. Dead right Bodge, it's almost negative rake because it was used for boring CI cylinders. Newton did a lot of reboring, in the shop and in situ and used three tools in tandem in the boring head. If possible he did the whole bore in one cut and said that he always got good parallel bores. Head scratch time again!

Stanley wrote:Sorry Maz, Young Jack has got it exactly right. Used on high class fastening especially when screws have to be frequently withdrawn for any reason. Now I'll have to rack my brains again!

I know those as "cup washers"........several sizes available !

Seals?

Glo. You're right in one way. Clue, they are made out of cast iron.

Piston Rings Eileen

For boiler pipes??

A big bunch of bracelets for a Bangladeshi Bride.

Eileen is right! Piston rings but what is it about them that is peculiar?

Not knowing what a piston ring looks like ( or does), I couldn't tell you.

Think about it Maz and look at the picture. You're good at these.

(oh...no pressure then! Gulp!)

So they are cast iron and not that big....cast iron seems to suggest to me they need to cope with heat or pressure ( but don't all pistons?)
I am going to suggest ( without a clue) that they come from a milking machine.

Or they could be egg rings for very flat fried eggs....