JS_Harris - 4:40 pm on Jul 23, 2013 (gmt 0)
I have sent two requests 7 days apart despite the first request being responded to with a 'no manual penalty'. I had what I thought(and still think) was a smoking gun in my traffic logs that showed heavy visiting from Mountainview and two other known human rater IPs in the 24 hours before my site took a nosedive. An algo didn't just come around after 7 years of being on top, ya know?
Anyway, I've improved the site greatly and traffic is returning slowly month after month. Quality is a cure to your Google troubles.