FAA CFI to JAA FI
I converted my FAA CFI to a JAA FI not long after the introduction of JAR. I went to a place who were able to conduct FI courses full stop. There was no such thing that they had to be approved to do the short course.
I did 15 hours flying and 30 hours ground as what has been stated. I then needed to get the 25 solo's before having my restriction removed. That bit did not carry over from the States.
Just keeping asking the CAA until you get the answer you want and then get it in writing.