I removed _all_ external links very early on (all pages now spidered and cached). Removing them restored a few pages that had clearly been penalised,
You removed links to other websites? Did you do this after Penguin?
I have registered with the offending site and blocked my pages (and all the backlinks have now gone)
Good idea. I am still wondering if a 403 will discount the links. I am using it, mainly to get the attention of the webmasters who weren't replying to my emails. It has worked in 80% of the cases, and I've had over 100k links removed (that were sitewide/margin links). Still, other pages link to me and I wonder if 403 will tell G it's not a valid link and I don't authorize it.