  A previous article was devoted to an analysis of the symmetry properties of a
class of first-order delay ordinary differential systems (DODSs). Here we
concentrate on linear DODSs. They have infinite-dimensional Lie point symmetry
groups due to the linear superposition principle. Their symmetry algebra always
contains a two-dimensional {sub}algebra realized by linearly connected vector
fields. We identify all classes of linear first-order DODSs that have
additional symmetries, not due to linearity alone. We present representatives
of each class. These additional symmetries are then used to construct exact
analytical particular solutions using symmetry reduction.
