Before 1921, sterling silver, 1921 to 1947, some silver but I don't remember the proportion.
I just mention it for information, I don't advise defacing the coinage!!!
Best Regards,
Swarf, Mostly!
Thankyuo SM for that information – very useful. They were collected by my father and somewhere I have the list he made with all the dates of the collection. I will have a look and see if there is anything valuable.
Peter