p38 4.6 thor auxiliary drive belt cover fixing bolts

My vehicle has not got the rh end of the plastic cover secured. No problem i thought as i could see where the correct bolt was fitted so just undo it and bolt it back up again once i had fitted it through the cover hole. I removed the bolt that is supposed to attach it but having taken it out it is not long enough as it it not a short bolt as per the manual but instead a long bolt that passes right through through the body of the pas pump and screws into the pas bracket. For some strange reason it appears that my vehicle therefore has 3 long fixing bolts for the power steering pump, 2 at the top and 1 at the bottom. According to the manual it is only supposed to have 1 long bolt at the top and 1 long bolt at the bottom with a short bolt to attach the rh end of the auxiliary drive belt cover. I can't fit the correct short bolt as the PAS pump has a clearance hole instead of a threaded hole in that position. Bizarre ! Only thing I can do is remove the existing long bolt (which should be a short one) and fit an even longer bolt to allow for the additional depth of the metal collet insert of the plastic drive belt cover. Has anyone else come across this aberration?
Maybe a previous owner drilled out the threaded hole and made it a clearance hole for 3 bolt fixing for the pump but i doubt that as it appears to have been cast like that. In any case if he had, surely there wouldn't be a corresponding threaded hole in the bracket to accept the much longer bolt ? .