For both
afaik. The needed retraining is to be determined by the flight school until the student is up to scratch for the flight test.
As for whether it differs where the license to be converted from was issued, I have no info on that. At least for a FAA ticket it was like that with me. Think that's the case for all ICAO-issued licenses though.
It's not much of an issue though I guess as not many low-houred guys will be ready for the JAA test in JAA environment under 10hrs of training.