Duplicate a widget?

I need to use the post-carousel widget in 2 different formats.
So I went into the folder pluginsso-widgets-bundlewidgetspost-carousel
And duplicated the file post-carousel.php, renaming it post-carousel-560.php and changing the functions and names in that file.
I also duplcated the template ad css files, changing the link to them.

When I go in the SiteOrigin Widgets dashboard, I see it there. I can activate it.
But when I go to add widgets in a page, it is not part of the available choices.
When I come back to the dashboard, it is deactivated. It will not stay activated.

What are the steps to duplicate an already made plugin?