truing a rear wheel

Bluestoesonnose

I've managed to buckle the rear wheel of my Giant TCR over a loose drain cover, it has straight pull aero spokes and a deep section rim will it be possible to straighten the rim or will i need a new one, I know this is a subjective question but the buckle is about 5mm over all LH to RH as it has slightly "S'd".

Oh and does anyone know a shop in the Plymouth area that could take it on as my LBS don't seem upto doing wheels by past experiance.

I should be Yogiing tonight so if anyone esle is going they could take a look...