More info on disc versions.
The weird 68mm spacing is meant for Hayes brakes. Hope made a C2 No9 to fit
" Caliper #9: This caliper is to be used with Manitou forks w/ 68mm hole spacing with 165mm rotors (??). No adapter is required (bolts directly to the fork tabs)."
And also "Caliper #11: This DH4 caliper is to be used with Manitou X-Vert Carbon forks. No adapter is required (bolts directly to the fork tabs)."
Hope also make an adaptor that bolts to a C2 No1, and then fits the fork.