I have a TK ticket ECN-IST return and a separate ticket booked on AC which has the routing IST-YYZ (AC), YYZ-MIA (AC), MIA-YYZ (AC) and YYZ-IST (TK metal). What are the chances of interlining ECN-IST-YYZ-MIA? And on the return, will it be possible to check through MIA-YYZ-IST-ECN? Any help based on experience would be appreciated?