https://ssz.fr/brdl/presse-manchots.jpg
I took it on Kerguelen island, that's not a very good picture but you get the idea, a nice engineering detail is that the handle that turns the spiked rollers also has a blade and slices the pressed penguins into smaller slices.
Most of the time though (at least on Kerguelen) penguins were only used as fuel to render seal oil. The penguin oil itself was not used as much because it was less valuable.
Edit here's another picture of the same tool which better shows it maybe:
http://2.bp.blogspot.com/_etp6gd-6WC0/TOpnWK6ZBYI/AAAAAAAABR...