They look like 1920-40s mass-market chairs based on the 1890s classical revival of the 1780s neoclassical movement because .... 1 - The back x-frames are absolutely flat, not finished to match the fronts like better furniture would be. 2 - the side rails in the neo-classical ones from the 1890s are straight or fluted, not squiggly like these. The squiggles are contamination from the popular "Jacobethan" ornateness of that era. 3 - The front x-frame is also flat, an indication it was jig-sawed or press-cut from plywood and veneered, and has the rounded lip that was widely used in that era. Better chairs would clearly show the individual pieces they were made from. 4 - The upholstery is inset in a delicately curved wooden frame ... the shape reeks of the 1930s popular style.

definitely not oak ... it's pine, maybe fir. I'm beginning to think it's one of the "mediterranean" pieces that were popular in the 1960s -70s, as interpreted by a workshop in Mexico or a home craftsman. It looks like it was made of 2x6 and 2x12s. The clue to Mexican origin is the smell of the wood if you sand it - their usuyal pine species has a pungent spicy smell. Not a "labor chair" - those have hand-holds on the side for the woman to grab during labor pains.

Molded fiberglass or plastic of come sort, chairs used in a reception room, perhaps in an outdoor dining area. Value? I have no idea. Are there any marks on the bottom of the seat? Look for molded-in logos.

if you want to re-stain, all of the old finish needs to be stripped. don't just wipe on a gel stain over whats there, it will look horrid. you can try sanding the flat parts until you reach bare wood, but those turned front supports are going to be difficult. Even if you paint, it will all need a very good sanding until it's smooth. i think if you kept the leather, gave it a good cleaning and conditioning, and painted the wood a satin black, they would look great.