  Nucleon-transfer sum rules have been assessed via a consistent reanalysis of
cross-section data from neutron-adding ($d$,$p$) and -removing ($d$,$t$)
reactions on well-deformed isotopes of Gd, Dy, Er, Yb, and W, with $92\leq
N\leq108$, studied at the Niels Bohr Institute in the 1960s and 1970s. These
are complemented by new measurements of cross sections using the ($d$,$p$),
($d$,$t$), and ($p$,$d$) reactions on a subset of these nuclei. The sum rules,
defined in a Nilsson-model framework, are remarkably consistent. A single
overall normalization is used in the analysis, which appears to be sensitive to
assumptions about the reaction mechanism, and in the case of sums using the
($d$,$t$) reaction, differs from values determined from reactions on spherical
systems.
