Hello, this is a weird question but is there an option to delete every project file except for the ones currently in use/referenced in the current scenes hierarchy?
Export the scene (And the scripts folder you're using), then it should copy just the assets used in the current scene into the .unityPackage it creates
Should be easier to move those files into a new project than the other way around
In addition to the above, please take not that when you "Select Dependencies" of that current scene you might
1) Miss out components what were added via scripting. 2) Have some of ALL of our components DETACHED of you choose to only select the folders rather than the scene itself 3) Will MISS out external plug-ins.
So for the 3 above its good to check that they're in.