First off it's a beautiful house, and the pictures don't put me off at all, but I'm a bit of a veteran house hunter and tend to focus on the bits that interest me. People do dismiss a house for the strangest reasons...
I think you should change agent. Last time we managed to choose really well, agent took brilliant photos (kitchen/diner was a good size anyway, but looked like an aircraft hanger with the angle he used) and we got 3 asking price offers on the first day of viewing. (We're not a million miles from you by the way, so this wasn't SE crazy market.)
Time before that, we went for the agent who seemed nicest, which he was but also hopeless. Switched to the cocky agent we weren't so sure of and he sold it in the first week.
If your house is unusual for the area, try to find the agent who has a lot of more distinctive properties for sale, rather than the one who is selling a lot of the smaller terraces.
I'd also think about getting rid of that fence if you can't get an angle which doesn't make it look like it splits the house.
And personally I wouldn't like a loo in the utility, so maybe try not to show that in the photos.
Also, if I were looking at your house, I'd be thinking of knocking straight through the back to make a big kitchen/diner/family room, as it's a shame that only your dining room benefits from the view into the garden. Obviously that's a changing tastes thing, but prospective buyers might be factoring in the cost of that. If it's a bit cheaper, and you can get people through the door, you can point out that that would be fairly easy to do. Our vendors helpfully pointed out that other people had converted their attics, which immediately made us think that we were buying a potential 4 bed rather than just a 3 bed house, which works better for us long term.
In terms of price, rather than dropping, consider offering to pay the stamp duty. Once you get into the 3% bracket it's a big sting in the tail when you're buying, and psychologically the vendor paying the stamp duty feels like you're getting something for free. When we were buying our current house, the negotiating point for me was to get the price down enough that we'd knocked the SD off the asking price.
Another option would be to say offers over £300k and see if that generates more interest. Doesn't mean you have to take an offer of £301k.
The only other thing I can think of, as others have suggested, is that being on a main road, and a degree of proximity to Hattersley, might be a stumbling block to selling at that price. Have you looked to see what other houses that have sold for that price are like?