wheels up,
Unfortunatley if you cannot get hold of a CAA approved sim or aircraft of the type you are rated on then you will not be able to convert your ATPL without doing a full type rating course on another aircraft. Another option for you would be to convert your CPL/IR and then get a JAA ATPL issued based upon your hours. The CPL conversion is training as required to pass the test and the IR conversion is a minimum 15 hours course.