Thanks Matt and Ralph. Before posting here I had been trawling through various examples on web sites and re-reading my copies of M. Langford's 'Basic Photography' and A. Adams's 'the Negative', seeking enlightenment on what constitutes a good neg. The responses here have been of great help.

I had started to pour the Ilfosol 3 in ten-seconds before the full minute, agitated as per the leaflet and started to pur the dev out at the 6min 20secs mark. It may well be that by being a bit slow of the mark in getting the Ilfostop into the tank, some over-development has taken place. Will try harder with the next roll!