Thanks for the experiments and advice. Finally sailed with the new toy today - and it slides very well. The sail is quite close to the boom and seems secure. Was surprised though, because the only way I could rig it was with the sleeve slightly off centre and the clew of the sail outside the port-side flange for the cotter pin. Consequently the whole sleeve sits a few degrees off vertical and the split-pin thru the cotter pin on starboard gest too close for comfort to the outhaul line rinning forward on the starboard side. The latter did not snag on my first day out but looks like it might sometime. Went back to check out the photos posted recently but these all taken from starboard and do not show this clearly - but the sleeve looks more 'vertical' than mine. Should the clew of the sail be to port - outside the the port-side flange?? The clew cringle in the sail on mine won't let the clew sit centred between port and starboard sleeve flanges. Comments from users appreciated.