Today I got back in to the garage to try again....success in the end.
I started by trying a vacuum bleeder on the front calipers and this made no apparent difference to the pedal feel.
I then removed each caliper from the car in turn. I did this to check the new seals etc. for any leaks (all OK) and then I pushed them out a bit by pushing the brake pedal a few times. I then rotated them around a bit (to see if any air was in the far side of the caliper to the bleed screw and brake pipe. I then bled them off the car. I pushed back the pistons and refitted the calipers.
The pedal now feels much firmer, shorter travel and the you can feel the brakes "bite" when I took the car around the block. I'll take the car for a longer drive tomorrow and try one last bleed but I think I've finally got all the air out.
