'97 F1 355 Spider, Brake bleeding, where am I going wrong?

I've cross posted this from the 355 section as I'm keen to resolve this today

Symptom - soft pedal that I can pump up but then is soft again next time, problem appears to point to air in the system

I removed the calipers to repaint them 2 at a time (one side then the other) unfortunately the seal I put on the front right brake line while the caliper was off failed and all the fluid seeped out. I refitted the calipers topped up the MC and bled the rear then the front quickly so I could turn the car around to do the calipers on the other side. No seal problems doing the other side, I refitted the calipers, gave them a quick bleed to fill the calipers then went about a proper 2 Man bleed, starting with furthest caliper and working to the nearest, ignition was on pos.2 as I read on here it's required although the system on my car appears to be the later Bosch type. I just tried bleeding it with the engine running but same result

All advice gratefully received

thanks

 

An update to say it's sorted, I pumped another 2 litres through using a pressure bleeder but it didn't improve. Turns out there was a huge amount of air trapped in the master cylinder, the unit has 2 bleed nipples, one for each circuit, 5 minutes and it's perfect