In 1869, the Virginia magazine "Land We Love" published an article called "The Valley Manuscript", which claimed to be part of the diary of "Margaret Lewis nee Lynn, of Loch Lynn, Scotland" transcribed by Fannie Fielding of Norfolk, Virginia. The remainder of the manuscript was promised in two future installments.
At the University of Virginia Library is a collection of "Papers of Stephen Philip Holt" which includes a copy of the manuscript and a 1948 newspaper clipping captioned "Old 'Valley Manuscript' Hoax".
Perhaps the discovery - following publication of the first installment - that the manuscript was a hoax is the reason the next two installments never appeared.
In any case, there is no Loch Lynn anywhere in Ayrshire and certainly none in the Dalry barony of Lynn, which was owned by the Lynn family for four centuries. The barony lies on the Caaf Water and has Lynn Falls but no loch. No loch is seen there even on the oldest historic maps in the National Library of Scotland.
In sum, we have:
1. No Loch Lynn on current or historic Ayrshire maps. 2. No reference in any historic record to a Loch Lynn in Ayrshire. 3. No 2nd or 3rd installment of the diary. 4. A 1948 news article proclaiming the "diary" a hoax.