[W126 Coupe] 380 or 500? help

[stefansj at canisius.edu]

Hey everyone, I recently bought another SEC and am haivng a bit of a problem. 
There is no emblem and has no records that I could find. it was actually found in 
an abandoned house that was set for demolition. It is a 1983 and has a 
European VIN but I do not know if its a 380 or 500. the VIN is 
WDB12604312003929.  If anyone has an idea how I could find this out, or check 
that would be great.  Thanks a lot,  Jas