There are a number of answers to your question.
I doubt I have to hand (certainly nothing like a complete record) of the branch you mention.
However, if you can give me just a bit more detail such as (broad) dates for Murdo or a few more names, I am sure I can find something on the Censuses.
Beyond that, the online Scots Origins database, should allow people to be found either since formal registration began post 1855 or in the Old
Parish Register records before that date [back in some cases to 1555].
One further thought. You might like to contact
Graeme MacKenzie, the curator at the Clan
Macmillan Centre on
clancentre@clanmacmillan.orgHe often knows of folks already researching a particular line.
Good hunting - and do contact me again if you can give me any more to go on or you think I can help