Oval Steering Column Mount on Sierra

[davylock]

Anybody have any idea what bolts/fixings are used for mounting the Oval Alloy Upper Steering Column bracket to the CP15 Plates. The reason I ask is the elongated holes on the CP15 plates are drilled to M13, but the Oval Bracket holes are wider ( 17mm ? ). Is there need for inserts of some kind which I'm missing. In the sierra manual it just shows two nuts holding the column.
Its a non adjustable column off an '88 Sapphire by the way, Dave.