Making sense of PO's alterations

[Riveted1]

Hi,
Got a couple questions for you guys. Just trying to figure out what all I wanna "upgrade" on this truck and what has already been done. I'm not the most mechanically inclined, so bear with me if these questions are a little "noobish."

This truck has a 350 out of a '73 Chevy truck, and it looks like the PO changed it over to power steering and power brake setup from the same truck. Is this why he cut the ds inner fender? So the power steering setup would clear? Or is there something else going on here? Maybe he switched out the whole steering column? Also, why would that "joint" on the steering linkage be leaking fluid? What exactly is it? And does that look like the booster/master cylinder out of a '73 Chevy truck?? I couldn't find a part number on it anywhere (that I could see)

Sorry again for my ignorance. I'm trying to learn! Thanks for your help and patience in advance!