it means its silver plated - made by Walker & Hall Ltd
Al-Oruba - Zabid - was created in 2008.
Al-Oruba SC was created in 1970.
At minimum, they're worth the value of the silver.
If they are old enough yes, but all silver quarters are worth more than face value.
Silver dollars have .7737oz of silver in each.
value will likely be only for whatever silver it contains
Regardless of mintmarks if it shows any wear at all the value is just for the silver at about $1.30
All silver Roosevelt dimes are common, if it has any wear at all value is for the silver, about $1.75
Any silver dollar that has a letter or number added to the coin reduces it to the silver value only, about $12.00
Buffalo nickels don't contain any silver.
Definitely if it's silver.