Nothing wrong with disconnecting connectors to inspect. If they crumble they need replacing.
+1 to the above. Ignore the BS flying about and enjoy your project.
BenelliSei, with all due respect, those connections are sound, even if the plastic is old.
Your 'enjoy your project' says it all. It's about a project and if you want one, you'll find one easily. When your project is to find a project, also fine, if that's make you happy. But be honest about it and don't present it as needed. That can create misunderstandings.
I have wondered about my own 47 year old harnass sometimes, but, hey, everything works fine and so far I have not found
one wire chafed. Maybe it has to do with my disciplin to leave things alone and just do what is needed.