Restoring a 1950s Stanley No. 4
Found at an estate sale for twelve dollars, covered in surface rust. An overnight soak in a citric acid bath took most of it off without touching the japanning.
Flattening the sole took about forty minutes on 120-grit paper stuck to a piece of float glass. I only worried about the areas in front of and behind the mouth; perfection elsewhere is not worth the time.
For sharpening I use a 1000/6000 water stone and a strop. A 25° primary bevel with a small 30° micro-bevel is plenty for pine and poplar.