I have just joined your community forum so I apologize if this question has been asked before. I have recently received some vital records from the Stato Civile di Gaeta. The administrator who provided the records not only provided me with the ones that I had requested, but he also went out of his way and provided me with some other related documents that I had not asked for. In addition to that, he returned to me money that I had overpaid.
I would like to send him a very sincere thank you letter and a gift for his trouble. However, I'm not sure if he would be offended by this.
If it is appropriate to do that, could someone help me with the letter. My Italian is not very good and I want to make sure I really get the point across about how grateful I am for his time and effort.

Sorry for the delay.
I think it's not necessary to send a gift, but a letter will be surely appreciated. If you write it I'll translate it for you.
Luca