Some (most?) of the alternators are Ford units used in other non-aircraft applications. I know of someone who simply takes it to the local automotive generator/starter shop and has it rebuilt for a song.
Can't help on the swivel joints, but if Cessna price is high and you have the part number, try surplus suppliers; I list three in the "Purchasing Parts" page of my "backup" website at
www.SkymasterUS.com (pink box near the bottom).
Ernie