Well.. Your title has me a bit confused.. pewter is an alloy of copper and tin.
Approximately 20% copper and 80% tin.
How did you ID. The material?
And what makes you think it's that old?
An identifiable mark Would likely have been on the handle.. for some reason I can't see where one was attached ..Mabey its just the photos.
It looks like tarnished silver to me.(silverware)
That is a different shape completely.
It is pear shaped.
Good luck with yours.. I would test it for silver if I were you.
Without a mark.. its doubtful you will ever date it.
Silver tarnished black and green.