Hi PGC,
An excellent report as usual.
See your comment of NGC 1427. Did you mean 1427 or 1427
A?
NGC 1427 is a fairly regular slightly elong elliptical-type eg that has an R.V about the same (ie +1300 to +1500 km/sec-odd) as most of the galaxies in the cluster and is a presumed member. Your description more closely describes this eg.
NGC 1427A is a bit different. It is a dwarf irregular not unlike the LMC but is somewhat elongated, dissrupted and undergoing a bot of a star-burst. It has an R.V of about +2100km/sec which would ordinarily place it in the background to the cluster, but ... it is in fact a member. It's peculiar R.V is pretty much due to its very fast in-fall to the centre of the cluster (from our side) where in time, gravitational tidal forces from the supergiant galaxies near centre and ram-pressure from the intergalactic medium it is rocketing though will ultimately tear it apart.
A quite interesting eg!
http://apod.nasa.gov/apod/ap050304.html
Best,
Les D