There is repositories on the GitHub which is not forked, but still is a copy or clone.
For example:
https://useful-forks.github.io/?repo=dirk-thomas/vcstool
where https://github.com/MaxandreOgeret/vcstool2 is a continue of the vcstool development: MaxandreOgeret/vcstool2#5
There is an option to search a repository by the name:
https://github.com/search?q=vcstool&type=repositories
I suggest to strip the repository name, for example, from trailing numbers and search directly on the GitHub.