I think the exterior of your flat doesn't reflect the potential of what is on the inside. When I go into a possible new home, I think about how I feel when I'm looking at it, your home makes me feel stressed and distracted, the collections of books, pictures, animal heads, Portmerrion jars and so many cushions that you can't sit on a sofa or lie on a bed. It is overwhelming. You've got some lovely possessions but they're hard to spot amongst all the everything everywhere.
The flat doesn't look well maintained and that worries me, things that I would be wondering: Why is there a wire hanging down in the hallway? Why did they take the tiles off in the kitchen? Why isn't that vent in the kitchen boxed in? Why are the floors covered in rugs, what are they covering? What are the piles of magazines and books hiding, cracks, damp? Will I need to replaster once all those pictures etc come down? Why are all the plants dead? And if you haven't fixed the curtains that are coming down in your children's room, what else have you neglected?
If it was mine, I wouldn't sell it now. I would put the children in the larger bedroom and put a room divider (bookcase?) in so that they both had separate areas. Are you able to make anything of the balcony by putting balcony decking or tiles down, covering the screening on the balcony rail? Can you put a chair out there for instance? Or a step ladder with plants on it? I'd be tempted to upgrade the dated kitchen and bathroom and hang new doors on the wardrobes, so that I'd get some enjoyment and use out of them, rather than do it exclusively for the benefit of a new buyer.
Can your Husband hire a storage unit for all his props and either expense it through his business or back to his employer? You could use some of it for the books. Or could he share them with a prop hire company? Do you really need to keep all of those magazines?