Awlin.. That is not an embosser. the main purpose of that little machine was to cut cloth material as to keep it from raveling, like you would use Pinking shears. not saying you could not use it for embossing tho.
I have 2 of those made by Singer and both have a wavy line and another one has a design like the one you posted. i have seen them turn up on E-Bay. It probably is listed as a Pinker.