Hi there Tankster,
It should be Dark Grey RAL7021.
Then again this could then be factory fresh, aged, sun-bleached, faded, wet...
I would not know what the vallejo range of colours can offer, but I would like to try Vallejo Primer German Panzer Grey (RAL 7021) # 70603 for myself.
Please check this link for a discussion on the subject:
www.militarymodelling.com/.../postings.asp
Very Best Regards
Johan