An account backup may be the way forward as this would include all the data on your account.
Certainly worth running it and giving it a go to see what data you get, and whether this is something you could use or adapt - Create a data backup schedule
The only exported file that includes all income and expenditure items is Nominal_Ledger.csv
The columns are
ID DATE NOMINAL CODE REFERENCE DEBIT CREDIT
The Nominal Code tells me which account it was allocated to (though not the account name eg Motor Vehicles)
No details Description I added - eg car Tax
No Notes
No details of what bank account
If anyone has another suggestion I would be grateful