Thanks for all the help but I'm afraid this is a massive fail. Without a simple map of button to role, i have no hope of working out which roles to assign. I tried trial and error, adding each role, testing, removing and adding a new role and have exhausted every possibility.
I have also noticed inconsistencies where the same roles assigned to the same user in two different environments (Production and Training) produce different menus.
I suspect the diabolical implementation of this product is behind the inconsistencies.
I will have to investigate the segregation of duties functionality to see if I can allow the user to view the receipts list without the ability to generate a new receipt.
Thanks once again for your prompt replies.
Regards
Simon