What are these ?

[Solvo]

Shape and size makes me thing shotgun primer anvils.
Likely rather old, new one have a pretty distinctive shape but they've very similar.

[duomatic410]

You used to buy them with the primer cup seperate then fix them to gether before reloading, mainly Eley sure fire.
Have a few left over from late 40s.

[DesG]

You used to buy them with the primer cup seperate then fix them to gether before reloading, mainly Eley sure fire.
Have a few left over from late 40s.

I've got a few pots of the old primers sans anvils. Life is strange.