Leachd is a small settlement a couple of miles southwest of Strachur.
I looked up the Dunoon Herald from December 1899 through to the end of March 1900, and found no mention of either man. Also checked Strachur churchyard for any possible inscriptions on family gravestones, but nothing there either.
The photo of the inscription has been edited to help make the wording more readable.
In the last photo there's snow on the mountain tops in the right-distance.
The following user(s) said Thank You: djb, QSAMIKE, Elmarie
The driver (who was American) of the bus from Dunoon to Strachur told me where the memorial was sited (he knew of the Boer War), and I'd only walked 100 yards from the bus stop when someone I'd arranged to meet came along and took me the remaining mile in his car.