As the bog referred to in the Question is not defined on a map, my reply refers to plots 1C, 2B, 3B, 4G and 8B on a Land Commission map of the townland known as Letterfad, on the Estate mentioned. The turbary over these plots, about one fifth of the area of the townland, was the subject of a private trust set up in 1916 between the Estate Landlord and six local trustees, for and on behalf of the Tenants on the Estate. The trustees were given powers to manage the cutting of turf, access, drainage etc., over the relevant bog. In 1958 the former Land Commission, using powers provided in the trust deed, revoked the trust over plots 3B (in part) 4G and 8B (in part).
It appears that the Land Commission did not own turbary rights over the plots listed in the trust deed, but simply managed them.