This might take some legwork to resolve. If I remember correctly (just sold it), the radio code for mine was handwritten on an Alfa supplied card. The code card you have ordered may well help.
I would suggest a call to Alfa UK though, and explain the situation. They could surely speak to whichever country the car was first registered in. Prepare yourself for a lot of phone calls, and a lot pf patience. Alfa UK are not the most pro-active when it comes to help.