Hi,
This is an interesting find and, at a first glance, it does look like there are many similarities between the scripts.
However, please keep in mind we have some guidelines about stolen resources accusations (you can read about it here: https://forum.multitheftauto.com/topic/46410-stolen-resource-accusations/) which this post would fall into even though it doesn't partain to a certain server. I'm sure you're well-intended so don't worry too much about it, this time.
There's not much we can do about this. What I'd recommend you is reaching out to the original scripts' authors (one by one, in private) and presenting them your findings. Afterwards, I feel like it's up to them to reach out towards YT and have the video taken down/updated with the correct/full credits.
If you find this individual promoting his scripts around our forums, Discord etc. you can let us know by reporting that specific post and we'll take a closer look.