Never give up on cast iron.  We made a trip to our homeplace over the weekend.  My mother-in-law knows how much I love cast iron.  She had purchased these kettles in a set many years ago.  Maybe as many as 50 years ago. I think she told me it was a 20 piece set and it cost about $20.00. ( thats says it was a long time ago)   She had stored them  in a building  many years ago.  We went on safari to search for them.  When we found them I thought “Maybe they are too far gone”.  But I brought them home and searched the internet for ways to clean them up.  First I used an equal part of salt and oil.  Rubbed that in(really good) with a cloth.  Then for the really stubborn spots of rust, I used a brillo pad.  Washed them in soapy water and reseasoned them. ( To season cast iron, coat the kettle with a light coat of oil.  Turn upside down on a cookie sheet and bake at 250-300 degree oven for about l hour)  I was so pleased with the result.  I couldn’t wait to post about it.  The largest kettle she called a pinto bean pot.  I can just taste how good beans will be cooked on our wood stove this winter.  Thanks so much, Judy.  So don’t throw that old cast iron out.  Re-do it.  It’s worth the effort.  God Bless.