Dark: Is that a play on Darth Vader? Welcome to the forum! And if appropriate, may the force (of phone collecting) be with you!
To answer your last question, yes that will need to be there not only to dial out, but to properly match the line to the phone, if it is wired correctly.
Since there are several variations out there, perhaps some photos of what you have would help. Since a photo can tell a thousand words, it is better if we can start there. Otherwise we can be here until Luke Skywalker takes over the universe exchanging various posts.
If you can, take a photo of the insides of the phone that show clearly (and hopefully in focus) how it is wired and what the mini network looks like.
Sorry for the teasing, but I am a tease.