IF you can prove good reason to possess said rifle, then that should be reason enough, book some days, have written proof from the "Paid day supplier" disclose all this information at the time of variation.
As for zeroing, if you have an "Open Ticket" zeroing shouldn't be a problem on the land you currently shoot over, providing the land is suitable. Failing that, find a local range that can be used. There is always the Paid Day Stalking supplier, you could always ask if they can assist you with zeroing? Some might infact request you shoot into a target prior to stalking to show that you can shoot so they might already have a 100m range for just that purpose.
Hope that helps.
TJ