At least you had a decent map!
Earlier this year, I was scrambling round Camelon Cemetery in Falkirk, looking for some of my wife's family. All we had a lair number, and a map which indicated which part of the cemetery it would be in. Eventually we realised that one or two of the graves had the lair number on the side of the stone or of the plinth, and so by counting between two we were able to narrow the search down to a two or three lair gap with no stone.
A few years ago, my wife investigated my mother's family. My maternal grandfather's family came from around Skye, Knoydart and Moidart, then moved eastwards and then up the Great Glen, including both sides of Loch Ness. So my wife had us searching (unsuccessfully) round Boleskine Cemetery and (successfully) in Drumtemple Cemetery.
Now she's planning a trip to Donegal and the surrounding area, where some of her folk came from.