Maybe open up the kitchen dining living room to the existing utility (removing the cupboard ) make the store your pantry. Then turn the second kitchen to the utility. You could have a separate boot room by extending round the outside store (presuming that is the rear of your house).
What's the upstairs like? With three staircases and maybe three front doors is this three houses knocked together? Do you need to retain all three staircases and the ability to convert back to seperate dwellings?
Excuse the ugly writing, was on my phone. I’d be inclined to keep the stairs on the left and incorporate them into a really big hall, turn the shower room into a boot room, make a corridor where the middle stairs are (reducing the size of the middle lounge, which could have a door from the new corridor and an arch from the room on the right). The room on the right could be squared off to create a big kitchen/diner, with a utility beside it (maybe add a pantry where the shades red bit is and move the utility along towards the boot room?)