  We have used deep I-band (F814W) images from the HST archive to study the
globular cluster systems around the brightest cluster galaxies (BCGs) in Abell
262, 3560, 3565 and 3742. Three of these BCGs have inner dust lanes and
peculiar structural features which indicate past histories of low-level
interaction and accretion. The deep I-band WFPC2 images have photometric limits
which, for all four galaxies, reach near or just beyond the GCLF turnover
point. Their specific frequencies are 8.24 \pm 1.65, 4.66 \pm 0.93, 2.58 \pm
0.52 and 2.62 \pm 0.52 respectively, all within a factor of two of the normal
range for giant ellipticals. We obtain new estimates of the GCLF turnover
magnitudes, which are shown to be consistent with an adopted Hubble constant of
H_0 ~ 70 km s^{-1} Mpc^{-1} on the ``Hubble diagram'' of GCLF turnover apparent
magnitude versus redshift, on a distance scale where the fundamental GCLF
calibrator E galaxies (M87 and others) in Virgo are at d=16 Mpc.
