Make up your mind what you are going to do. If you are going to leave it stock, and have a ball driving a 70 year old car as it was made, which is really a kick, then buy new wheel cylinders. If you can't imagine driving an old car that compared to a late model car has very low power and not very good handling and poor brakes, then swap it all out for what you want. I drive a similar car every day, stone stock and I love it, but it isn't for everyone. Short trips or on a longer trip taking your time at low speeds. I LOVE driving this car every day, but it may not be for you.
Make up your mind and do it, I bought rebuild kits for my car and pulled them apart and said no way, they were pitted, they were not rebuildable. My life is worth more than that and I bought new ones. Now, mine were extensive like that too. Until I spent the time and tracked down the proper part number and called the parts store that I get most of my stuff at here in town, a REAL parts store. They had them in stock! And they were something like $10 each.
This may happen to you, or you spend the $70 each and you have brakes that work. If you plan on driving this car I would replace all the lines and hoses too. They make a new brake line that is a dark green color, you can bend it by hand real easy without kinking it. Most every piece you will find is a standard length or close enough. If it's too short you add a piece and most real parts stores will even flare it for you. If it's a tad too long you just make it work with a larger loop or bend or something. I put all new parts in my car before I drove and I am damn glad I did. They had the master cyl in stock too!
If you are going to leave it stock just do it all and get it over with so you don't have to think about it.