Here you have all the information about how to modify bthe Tamiya to get both versions: M51 47° welded hull ( the Tamiya one) and the M51 cast hull ( nick Aguilar one).... step by step.
http://www.modelersite.com/en/2040/b...kit-1-16-scale
No special materilas are neccesary others than some aftreparts from Axelmodelbaun.