I have McLELLANs in Ayrshire. They do not seem to be related in any way and were from around Lochwinnoch (RFW)  & Kilbirnie (AYR). In searching the spelling can be the bugbear. Try McLELLAND, McCLELLAND, McHELLON, McLELLON, and even one with a McCLLELAND, and I would suggest any possible variation of these. Anne Maye