Be carefull with the type of "sand" you use. There are other options to use as your abresive material besides true sand for example they use crushed walnut shells sometimes. I would recommend trying to use something called Black Beauty. It may be a little more money but you'll avoid the chance of silica exporsure.
You are right but this one is in such poor shape that it needs a painting and full restore. you can still find the same paint that was used 50 years ago. Its worthless in its current condition. I have been collecting machines and soda stuff for a while, when they have minor cosmetic problems its best to leave alone like you said, but this cooler is so bad that if nothing is done it will continue to rust from the inside out and fall apart. Its a shame that it was allowed to come into this condition. This is a very rare westington house cooler from the 30's I am not even sure now if I am willing to put the time into it.
is there major rust? They used to make a product call "osmosis" that would revert the rust. I used years ago when I was restoring cars. It worked well. You had to wire brush the flaking rust off, then brush this stuff on. It was amazing, it would turn the rust back to a bare metal color. You might try an auto body supply place or a paint store.
Pelagicmagic you are right about it being in bad shape, but it took 70+ years to make it look like that. It is full of patina that you can not buy anywhere, or replicate. I am a collector myself and have been collecting antiques for a couple of years. I have a couple of coke coolers that are from the 40's, and one vinyl one desigened for boats so it would not scratch the wood decks. I was told it was worth around 150 dollars. I know you want it to look nice, but anyone with enough money and time could do the same. Keep it how it is, to let poeple know it is actulally from the 30's not some re-pop you can buy anywhere.
No i only small coolers, but let me know if you want to get rid of that shameful, horrible, hunk of junk. It is probably going to fall apart in a few weeks anyway. Why would you want rust stains at your house. PM me to let me know when you want me to get it the hell out of there.