You're welcome Frank.
That would be Christofle's early silverplate mark (c. 1844-1862).
Their later silverplate marks were in a square and then a rectangle.
Yes, they are well known for their excellent quality silverplate.
The number 58 likely refers to the amount of silver in grams that it took to cover a certain number of these pieces.
Don't know how many pieces that was, probably around a half dozen.
http://www.925-1000.com/a_platenumbers.htmlPat.