Stanley #4 1/2 type 19 restoration or junk?

Agreed.

The sides of small smoothing planes don’t need to be square to the sole, though it may help if it does if you use it on a shooting-board. Even so, its main function is not to reference a cut from the sides as with a shoulder-plane or the like, but to flatten boards.

What is important is that the sole is flat and that the frog assembly is seated properly in relation to the mouth aperture and the seat of the blade. Frequently the cap-iron needs some attention at the seating line on the back of the blade, but all these are standard fettling-issues that would be carried out on any new plane.

There’s lots of information scattered about in the usual reference points online about how to do all this. Much of the techniques can be opinion-led, but if you aggregate the main points you’ll get there.

On the sole photo there seems to be a low spot across the front side of the mouth.

If you want to use a plane as a smoother you should possibly keep on with the sole flattening until you eliminate that low spot.

You need the plane sole to press firmly the wood fibers right up to the mouth opening in order to reduce the possibility of tear out.

I’ve been reading this with some interest. The accepted theory is that plane soles need to be absolutely dead flat, end to end. That’s the ideal, anyway.

In reality, hand-made woodwork seldom needs engineering tolerances to be good or effective and there are many old wooden planes that defy that edict of sole-flatness and work well.

What in fact makes an appreciable difference to a planes’ effective working is that the area surrounding the mouth aperture, say about ¼ to 3/8 inch wide each side is flat and in full contact with the wood both sides of the blade tip. Small differences in level on the remainder of the sole can often be flattened out little-by-little over time, but a blade tip that has the mouth of its sole somewhere in mid air will seldom give acceptable results….. mostly it will chatter and vibrate.

All that is true for ‘European-type’- planes which we work on the push stroke.

Go East – particularly to Japan – and their planes work on the pull stroke – toward the user. Traditional Japanese planes are invariably wooden and adjusted by wedges. Set, sharpened and tuned, they can produce staggeringly, accurate results. Turn the plane over and you’ll see that, rather than to flatten all the sole, end to end, they will ensure a clean, flat area surrounding the mouth, plus about ½ inch at each end that is in contact with the work at the nose and at the toe. A small amount of the surface of the sole in between these points is relieved, scraped away, only a fraction of a millimetre but that is all you need. Effectively, the plane sole is in contact at only three points.

The easiest comparison is to compare this to an uneven floor. Sit on a four-legged chair and it rocks on the two dominant points, then transfer to a three-legged chair – the difference will be immediate – all three points in positive contact.

Good luck with it.

Yes moving the frog forward will help but also, you need to get your sandpaper down to about 1000K or finer and then strop it. Question for you…. looking at the picture with the square on the soul… have you checked your square to make sure it is square? That’s a lot to be out and I would think there would be some visible damage. Keep working on it. Looks like a nice plane and you will be proud of it when you get it finished.