Recently, I picked up a silver fruit knife that, thanks to people on the website who have helped educate me on them, I've been able to identify as made by Gorham in the 1855-1860 period. Unlike the last one I acquired, "Sterling" does not appear on the tang. Does this mean the knife was probably made of coin silver? Or possibly are the hafts silverplate? This type of knife is so commonly found that it would be a help to get some guidance on how to gauge what they're made of.