What am I?

Cover the clues so you can only see number one. How many clues do you need before you know the answer?

1. I was used before and around the time people first started to plan Pukekura Park.

2. There was sure to have been one of me somewhere on the Brooklands farm once.

3. My round part stands about 35cm high and I am about 20 cm wide.

4. Turning my handle gave my regular operator quite a strong arm.

5. A liquid turned more solid-like inside me.
   This liquid began in a cow but ended up on bread.

Answer in the next TreasureLink.