Hi Marcus,
OK I can tell you what I know as I only got involved on this the summer, some 12 months after the SEO contract finished with the old web provider, nothing actually happened thereafter.
I don't think we are working off a penalty, however we did have a lot of problems when the new site was launched last november with duplicate data 1000's of 301 redirects, 2500 pages 404'ing etc. This has only resolved it's self int he last 4 to 6 weeks after a lot of heart ache and dropped revenue. 404's are at 840ish and dropping daily now, duplicate content is down to 28 urls and dropping too. All because of bad advice hence why we are now looking after things in house.
Competition are your Amazons, Marks & Spencer, towels.co.uk, Christie Towels, Linens limited. I think we can better some of these for sure.
In terms of link build previously I have no idea how this was done. There was no blog, no social media (still none but looking at this) so I guess normal linking building routes.
There link profiles are massive in comparison to ours and i wonder how many we have lost because of all these bad 404 pages etc. So i would like to capture and re-direct anything that got value before the fall away for good.
I have tried signing up to link detective but they are not send a authorisation email so can;t gain access frustratingly.
Any more info i can provide let me know.
Thanks Craig