Norman, thank you so much!!!
I had all but given up hope that this, like so many items of earlier military field and campaign kit, would attract much attention. You always come through my friend!
These photos showing these in use in the Crimea are perfect, I could not find images of these in use as I did not have access to the references on this topic, researched many years ago. The 'bookmobile' has limited library space
Thank you for posting the subsequent issue type, and it is interesting these seem to have been colloquially called the 'Italian' form and apparently the 'oliver', both curious terms.
It seems that examples of the round type I have posted found later use in degree by Confederate forces in the Civil War here as well, but have not yet found more detail on that.