That explains the “rustic” finish. If it were a full height wall it could look really good, but as it’s such a small area it just looks untidy. I’m not sure re-pointing will make much difference as the bricks are different sizes and rather higgledy piggledy in layout. I think plastering will be a huge improvement.

Way late to this thread so probably too late, but want to add if that's an external wall then please don't seal it. Looks like an old property with lime. Needs to stay breathable. If you steal it any moisture can't escape and you'll create damp problems. Perhaps whitewash with lime then add a breathable clay paint?

Hi, In need of a bit of advice or guidance regarding the possible need for damp proofing to an existing external wall that now becomes an internal wall after an extension. I plan to keep it as exposed brickwork as attached visual. The problem (or maybe it's not a problem) I have is the new extension lower floor level (blue line) is a lot lower then the existing DPC (pink line). Is there a chance moisture will run up that external wall and create damp issues? If so, what would be my best course of action? Hoping that all made sense. Many thanks in advance.

If you have already had a green colour and a smell of fungi I wouldn't paint it at all. I would hang some really huge bright artwork over it to provide the colour lift you are seeking. Give it some time and see if the green and the fungi smell return. If they do you will have to treat it for damp. You could also fix a bright board in front of it with a big air gap behind. You might need a dehumidifier as it has rained non-stop lately and that direction of wall will hardly receive any sun.