Hello Peter,
Can your friend go back to the seller on the off chance they still have that detailed history somewhere? If you don’t ask, you don’t know!
It’s worth going to see your nearest Audi dealer ( armed with your V5) and enquire whether there is any recent computerised service history on the Audi database.
If both of these draw blanks, then I guess you just have to do a comprehensive service on it now, and continue to record its history under your ownership.
Please let us know how you get on Peter.
Kind regards,
Gareth.