I'm aware of why it was called 17 Windows, and for anyone who isn't, take a look at this image
http://visitmarple.co.uk/photos/displayimage.php?album=search&cat=0&pos=11All I was saying is that if it were mine and I were carrying out the alterations I would have made the number of windows fit in with the existing name.
The building has only been a shadow of it's original self for many years, since the weaving workshop was lost to fire. Looking at this picture with fresh eyes it looks to me like the place that the existing building was stapled together recently before being rendered over is in line with the join between the house section and the weaving workshop. It would appear that the right half was rebuilt as a mirror image of the left after the fire but probably the brickwork join was not done properly, which is why it came apart and needed stapling.
To be honest I don't think the house itself has been attractive for a very long time and it certainly doesn't retain much of it's orginal history, which is why it's not listed. It surely would have been if not for that fire.
I think once the landscaping is finished and planting matured a bit, and the property is being used, it will look better than it did before.