vintage architectural doorknobs, white porcelain

Lot of two pair (4 seperate knobs) old, Arts & Crafts vintage, architectural salvage white porcelain door knobs with metal fittings and square shanks. The knobs measure about 2 1/8" across and about 1 3/4" high with the metal mountings. The shanks are about 5/16" square.

The knobs have a little light wear and scratching. A couple have smears and/or dots of old paint.