Need help with parts ID

[z-bikes]

Some parts I recently acquired that I don't know what they're from. Any help appreciated.

1. Weird seat post with indents.

2. Kickstands

3. Stem. Top is polished sides not.

 

[ratina]

The stem looks Schwinn to me

 

[bairdco]

Seat post is probably from a tricycle that uses a square "Frankenstein" bolt instead of a seat "clamp."

The bolt presses into the indents to keep it from moving.

 

[rustjunkie]

Kickstands may be Columbia?