Fox also offers Flak’s wingmen as a “do it your self” mod.
You have to add the info in but he provides a more than comprehensive guide on how to do it.
The only problem you will face is that the way Fox’s wingmen work messes with functions needed for single player to operate.
So you have 2 options.
Add them your self and just play sp with bugs
or
if your only wanting Sp cos you play by your self
if you have finished the story missions and just wana keep roaming.
then play open single player. basically singleplayer with out missions.
Wingmen will work fine in this mode. And even if they didnt Open single player is just the same as Multiplayer by your self.
Just make your own server by starting the server.exe
put a password on it. and make it not for internet.
then just join and play by your self.
As for not doing the work your self.
Well Flak88 does it perfectly as its the originator.
But with foxes awsome info i coded wingmen in to the Rebalance mod which in manyways is slightly more like original freelancer and not as advanced as Flak so you might find it to your liking.
But if you just want vanila then Wingmen tutorial here