[zagato750gt]

Hi all,
I would like to complete my '63 101 Spider with a hardtop.
I realise that they need bodywork skills to make them fit correctly, thats ok.
What I want to avoid is ending up with a passo corto one.
How do I tell the difference between a short or long wheelbase hartop?
This one is for sale at the moment in Germany, but it is 300 miles away from me.
Which dimension could I ask the vendor to give me which would identify the model it was made for? He says it came off a 1958 750D.
Or is there a Pininfarina type plate difference if it still has one?
It is steel and has a glass rear window, the lining is cream colored.
Thanks for your help
Nick