Errrrrr, well ummmmmmm, the locals that I'm related to & acquainted with, whom are still alive taught me that the "Surname Of ..." designation is a legal moniker concerning land holding and elevated status, perhaps to a Baronetcy, which may be periodically re-issued, dependent on dormancy.

Considering the majority of historic Cameron territory traveled south to the northern shore of Loch Linnhe, just a wee bit north-west of Fort William, I assume I was taught that "Cameron of Locheil" was derived from what was, at some point, "Cameron of Loch Eil" or something similar.

My comment had to do with credibility issues regarding the site sourced for Mr. MacDonald, rather than engendering a dialectal, register or semiotic debate.
Besides, Mr. MacDonald spells it the way I was taught, so...when in Rome 'n all that.

Domehead