In theory you can do the renewal elements in any JAA State however, in practice this may be a little different. In the UK you will receive a signature on an Instructor Form 3
http://www.caa.co.uk/docs/33/SRG1135FF.pdf for the Seminar, then you will need another signature from a FIE for a FI test who in theory can sign your FI Rating (well if it was issued in the UK) but not necessarily an Italian one. So the paperwork may have to go to the DGAC in Italy. Alternatively, you should check with the DGAC what they require, their paperwork may be quite different and they may require it on their forms.
Regarding the FI test, you may find that in the UK it bears no resemblance to anything you have done in Italy. Try reading this document:
http://www.caa.co.uk/docs/33/Stds%20...ement%20v1.pdf My advice is stick to meeting all the requirements in one State that is acceptable to the DGAC.