Som of us haue reuised oure spelynge syns þe 1100s.

It is still currently spelled "Domesday book". Go ahead and try and find it via your incorrect spelling and post the link to us.

Or maybe you're referring to the modern novels which are titled "Doomsday book"?

For the record, when you misspell it as you insist on doing, the top hit is the correct spelling with a link to the correct version: https://en.wikipedia.org/wiki/Domesday_Book. Actually pretty much every top hit is the correct spelling, which should give you the idea your misspelling is just that, a misspelling.

Here's the Grammarist entry on the difference: https://grammarist.com/usage/doomsday-vs-domesday/

That should make it clear to you.

Instead of doubling down on your ignorance you could choose to learn when presented new knowledge.