Thanks
I had a look at the FAA site. The problem is that the original licences where the FAA licence is based on Are no longer available. I will check if the Dutch CAA still has them in their system. My ATPL and medical are valid.
I will check for the conversion but seems that takes time (months). Since i only want to do some training not needing a licence or check at the moment, i might just go to Canada for now. No need there to get TSA approval. And also the temp conversion of my JAA ATPL seems to be easy