AvroDriver,
If you have the required hours to be issued a JAA ATPL and hold a FAA type rating, than yes, you can do your skill test on type and have issued a JAA ATPL with the type rating on it. You need, however, to find the aircraft by yourself and schedule the test with a CAA examiner. I heard that it takes 6 months to get a date for that kind of test with a CAA examiner.