Repairing service of a recovery truck

I am the Fleet Maintenance Officer of xxxxxxxxx and I am looking for a reliable company able to repair or even upgrade the recovery truck presented on the attached photo.
Vehicle chassis is a MAN TGM 18.250 4X4 BB, the whole system was purchased in 2011 and it is designated to recover civilian armoured 4x4 vehicles (Toyota LC200) with the total weight up to 4.5 tones. Due to the extensive use it is needed to check and adjust the platform geometry and its alignment, refurbish the sliding bed bus