That will be fun, given the Rules of Origin protocols. If something is assembled in GB, if the parts it's assembled from aren't all GB in origin, they all have to be accounted for and if a certain proportion aren't GB (I think it's by value, the proportion is IIRC somewhere around the 50% mark) then it's not a GB-origin item. I assume that the Irish article means GB rather than UK, as NI is EU (rules-wise, anyway), and UK = GB + NI.