Your problem will be the CO2 capsules.
They have a ban on compressed gasses in the RM system.
They seized and destroyed a 500CC buddy bottle that I sent last year - it's mental, they say they don't want compressed gasses then they FLY anything considered dangerous to Belfast and destroy it. I pointed out the bottle was empty but they didn't care. I got the whip and valve back.
So you may get the pistol back, but I wouldn't hold my breath. If they do seize it you won't get compensation either because they will judge that you have breached the contract you had with them.
Good Luck