I should mention that if you go with the assumptions that Bill Marcy makes in his analysis at http://home.hiwaay.net/~langford/seat1.jpg and http://home.hiwaay.net/~langford/seat2.jpg as being good enough, then 3/16" AN3 bolts should be sufficient, but with no real margin...
Mark Langford, Huntsville, AL N56ML at hiwaay.net see KR2S project N56ML at http://home.hiwaay.net/~langford
