After rather intensive research throughout the British Iles, Scottland and Ireland, looking for the origin of the name Muckleway for an ancestor of mine in Wales. I do believe all these names have their origin in McKelway, which was a surname native of Scottland and goes back very far indeed.
Whenever a name is too few and far between..it probably was altered or misspelled or someone just wanted it that way ;-) You probably will have to (like me) go over Ireland to get back to Scottland on this one with this name. It is a very old name and goes back centuries...have fun!