You mentioned that Sinclair was one of the surnames that some of the MacGregors assumed, and that this has been documented. Can you retrace and find the source? You've got me very intrigued, and now I'm going to have to pursue this! The problem thus far that I can see is that there are few Sinclairs found in extant Argyll records (as far as I'm aware, although I certainly haven't looked at every possible source) until the two mentioned in the 1692 list of "fencible men." This is 90 years after the proscription act. Wouldn't we see many more Sinclair/MacGregors after three generations of time?
Anyone else out there who can add some tidbits?