To date, there are 3 Gibson PSA 8s and 3 PSA 7s
One Seaver 8.5, two 8s, one 7.5, two 7s--also 2 9Qs (counts as a 7) and 2 8Qs (counts as a 6).
http://www.psacard.com/pop/Detail.aspx?c=95017
Grades are way below those of the regular set. Highest achievable baseball score as of today is 8.46 which I believe is the lowest post WWII score for Topps outside test and Venezuelan issues.