I own centralsaddlery.co.uk and I have been hit by the same issues. We have been working on content and video work. I have also been getting rid of all my dead products. cleaning house!
I have added category descriptions, up graded product descriptions, improved blog plus found gust expert bloggers, added a tips and advice section containing articles and videos, I have hired an actor to make product, category and informational videos and I have also added brand descriptions. I hope all of this will have an effect but as yet 6 months on I have had no increase. Costs have rocketed and the site is much better and improving on moz yet no sign of google liking us more.
Im not sure this will below you but hopefully it will let you know your not alone.