Floor not entirely floorboards

[MuBuPlu]

Hello.

I'm looking to restore the old floorboards in my living room.

I ripped up the carpet and found that the previous owner had replaced the fireplace with a concrete slab and there's also a block of wood where floorboards could've been.

I want the room to be entirely floorboards, but how do I do all this?

What do I do about the concrete and wood slabs? Do I need completely new floorboards?

Pics attached to illustrate.

Thanks.

 

[Tigercubrider]

Easiest would be to "borrow" some floorboards from another room.
The slab will be original or a replacement for an original. You'd need to remove enough to reconstruct a floor and stagger the "new " boards so it doesn't look like a patch

Or cover the whole thing with engineered wood or laminate