Could it be Achnacly instead of Achnachy? An h i handswriting style could look like an l.
There is an Achnacly between Reay and Halkirk - check here https://canmore.org.uk/site/184420/achnacly
and here: http://www.scotlandsplaces.gov.uk/di...-volume-09/124
and here: http://www.caithness.org/atoz/brubst...sterplaces.htm
Hope this helps!
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