I have Muirs in my family that were Scottish missionaries out in Morocco from c.1890-1940. I have managed to source some passenger lists for the ships leaving the UK to Morocco and other vital records registered by the British Consulate. If you haven't already done so, on the Scotland's People website there is the possiblity to look at minor records, including consular returns. If you require any more information on this please get in touch. If you find out anymore about Morrocan records I would also be very interested.