From 1922:
Those who do not dislike the flavor of uncooked eggs will find this dressing easily made and very good. Take two eggs and half a cup of salad oil, beat together, and then beat in the juice of half a lemon and half a teaspoonful of salt. This dressing should be freshly made, as it will not keep like mayonnaise.
Egg-White Salad Dressing
Most of the eggy flavor is in the yolks. A dressing may be made of whites only, similar to the above recipe. It will be a little stiffer and have a delightfully creamy flavor if melted butter is used instead of oil. The egg white is inclined to separate slightly, and it should be whipped up a bit just before serving. When one prepares a quantity of mayonnaise there are extra whites, which may be used in this way immediately, keeping the mayonnaise for later on.