If Zorki works for you keep it. Do not waste energy on equipment. You will find that Leica will be just on your way and you will always try to hide your low creativity behind the Leica camera. High cost equipment is proved to be very bad choice if you really do not need it. Just in the case if you think Zorki do not assist you good enough look further.
Leica is nothing better than Zorki. The best camera is one you like and it make pictures you want.