Well, depending on the year..... the DS II was rigged exactly the same as the DS I. The mainsheet wasn't changed to mid-boom on the DS II until the 1974 model year (had "crosby mainsheet rig" just like the DS I for 1971-73).
I have attached a copy of the Spindrift DS I Owners Manual, it describes the rigging of the mainsheet. The pictures aren't completely clear... but I'll add a diagram showing the basic layout. I had hoped that the pics of a Spindrift DS I would help.... but something looks "funny" about the traveler on that boat?
You could convert to the mid-boom rig of the later O'DAY boats, it would require adding a different block and camcleat assembly in place of the stock setup from Spindrift on the CB trunk and a maybe a new block on the boom. It is a simpler setup and keeps the aft end of the cockpit clearer, but I think the stock Spindrift setup may work better and make the sheet easier to pull in.