The engine number can be found in the registration papers.
Can I fine there the frame number?
I can't find the VIN number in the registration papers.
The only thing is: ZDM 750P 750065 what Information I can get from this about the motorcycle?
TNX

If there's no tag on the frame (left side) the number is also stamped into the headstock (right side).

The problam is that i bought the motorcycle from Italy, i have the registration papers with me but the motorcycle still on its way.
I thught I'll find the VIN in the registration papers and not just on the frame.

It should be indicated in the first Section of the logbook (should be a big paper folded in 6 parts printed front and back), at the bottom you should read few lines saying something like:

CLASSE VEICOLO - MOTOCICLO PER TRASPORTO PERSONE
FABBRICA/TIPO - DUCATI MECCANICA SPA / ZDM*****
OMOLOGAZIONE - OM*****
TELAIO ZDM 750P********

where the * can be letters or numbers

On old vin numbers I am not sure if they had the 16 digit sequence, having said that, the number could have a totally different sequence as some frames were for other markets (USA Canada) and sometimes they had weird numbers (I got a frame of those myself)

This what i have found (see attached)
What details about the motorcycle I can dig from this?
Another question from this paper:
87 is probable the manufacturing year?!
What is the PISA 28/03/90 ? Is It first sale, 3 years the motorcycle sat?

The frame # is indicated as 750065, it seems a very early number to me, that would explain the 87 in the "anno di immatricolazione" field.

What is wierd is the other date which should match the year "87" unless we are talking of a bike that was registered but not recorded, basically they registered the number plate (1987) then waited until to 1990 to record the registration against the name of the first owner; Thbeorietically no more than 60 days should occur between registratrion and recording, but there is no fine for any delays provoided the vehicle is off the road (the case of it sitting in a factory or in a dealer showroom)

that is the only explanation I can give.... often dealers would get vehicles in theor stock and these will be "registered" without ownership, this way they can play trick (get extra discounts from the manufacturer, show higher sales , etc, etc) the same applies to the manufacturer... my 1991 907 was built, according to official records supplied by ducati, in 1989... most likely they printed the frame number on a production sheet just to trick investors on the production numbers...

As for the short VIN# 750065 , that is something I saw in a 1986 Yamaha RD350 I used to own, they took only the last 6 digits of the VIN when the bike was first registered, most likely on the head stock you will find the complete number in the form of ZDM750P000750065 or something similar

750065 suppose to be 1986, i think so, in 1986 ducati made 1023 750paso
another question:
like i have told you, in the motorcycle paper the manufacturing year is "87" and not 1987, is it common to see it like this?

Thanks,
I did what you recommended and spoke with Ducati, and they told me that the motorcycle is 1987.
BUT, for some reason I'm still not sure.
iook at the attached paper.
what is it?
why it is Written 1986 and 1987?

It says it was built in '86, registered in '87 and model year '86.