How to tell the maker when a piece is unsigned?

[prodigalthriftstore]

I have been going through a large collection of costume jewelry, and found this piece. While researching another piece I found a site that shows one that looks just like the one I have,and they are claiming it as a unsigned WEISS.

I am new to this, so how do you know? Is this an unsigned Weiss?

[oldasdirt2012]

Beautiful pin and with out the original box it came in or a picture in one of the jewelry books it would be hard to convince someone it was a real Weiss. I can think of a couple more jewelry makers who could have made a comparable pin.

[realitycheck-7]

You can't really tell.