Cleaning door

I have a masonry fireplace built about 1930. It has an 8x10 inch cast-iron door which opens from outside the house for ash removal. I would like to replace this door because it is badly corroded. Two questions: 1) I don't know what to call this thing. Is there a name for this part which would help me find it? 2) Any suggestions on where I could buy one? Can I get a new one, or do I have to look for one that's been scrapped?

Thanks for your help,

Ulrich Merten

They are called ash cleanout doors home depot may even sell them but your best bet would be a masonry supplier
cast iron can still be bought and also steel versions, Bring your frame along to match up sizes or cut a piece of cardboard as a template. Mot the most part they were friction fitted !930 may actually be motared in. You might have to purchase a smaller one and motar it in