I think that the fashion is for open kitchens with a connection to the outside so you might explore if this room could be knocked into a room next door. If you post a plan of the house you will likely get some suggestions you had not considered. If you want to keep the space as is then you probably just need a lighter kitchen. The wood finish combined with a cathedral arch on the cabinet doors betrays their age but the floor and worktop does not. As a short term refresh you could have these cabinets painted and I would choose a lighter colour such as a soft white, or a warm neutral. When you do come to replace your kitchen your cabinet choice depends on your personal taste, any things that you have to work with and how big the space is..... for instance lots of sleek handleless designs have horizontal lines and drawers- you can only accommodate and appreciate this in a larger space. If you do knock this kitchen through to another room then you will also need to consider the furniture and the floor you want in their- if your taste is comfortable and homely then a sleek white kitchen may fight with this and you may prefer a cabinet door that looks more like furniture and then choose a colour to match. The photos section of Houzz has lots of inspiration.

If you read over a breakfast bar (sorry, no time to look properly) then you may want to be able to switch the light above that on and off separately to save lighting the whole place. Ensure that recessed lights are spaced according to the ceiling you have after you've put wall cupboards in place (tall ones flush to the ceiling also saves cleaning and you can use a slim stepladder to reach stores etc in the upper shelves) and ensure that lights are central above work surfaces so you aren't working in your own shadow. My electrician refused to believe this would be the case and we had to install a second row of lights to correct his error. I hope this helps. (You'll clock that my lights were not put in well!)

Idea: Keep the downstairs toilet/utility, but have the chimney removed and move the door to the middle of the wall. I've placed the cellar door in the dining, so the full kitchen wall can be used.

Its a great space. I quite like the floor but there is a lot of it and its a bit flat looking, you could add a sisal rug under the table to break it up. I would also sell the black fridge and replace with something smaller, lighter and more discreet and a pale coloured bin too. Not a fan of the brick and think painting or plastering over it would create a sense of space and light. Maybe add some rustic mirrors to bounce the light around? The table is quite dark and heavy so again you could look at other options, though it does sit nicely with your other furnishings. And as others say, painting the units and beams will also make a big difference.