Yep. On your radiator you might have to go with aluminum and plastic tanks to keep car running. Wash it out with diesel or B12, stop any future corrosion. Pack what you have real good in mean time until you can find replacement . The cores are around, but the side tanks will be very very difficult to find.I'm thinking you can find an original brass radiator somewhere in America however, It will pose to be quite difficult due to aluminum radiators have all but replaced brass ones AND all the old guys who had radiator shops back in the day when brass ones were the norm are either out of business or dead. There must be places for radiators like Cooker tire who specialize in old style tires for radiators.
On the tank you will see the solder line. Back when I started we used a shop in Downers Grove, owner was a very nice older black fellow..., always had beers and stories. Told me he started back in depression days when he was a kid.
Process is simple... Heat the radiator and solder melts, tanks come off. He stocked all the common size cores, plus he made custom when needed. Once you get the tanks off clean up make sure tank thickness is still good, resolder to the new core. Pressure to 15psi in a water tank, check for bubbles and when good, clean, dry and paint.