I bet you say that to all the boys? 
Only on a hot summers night.
All sorted, Pistons out. Three days in penetrating oil then reassembled blocking off all the exits and pumped grease through one nipple. Thanks for all the tips and the more interesting side topic. I’m a Yorkshire gold drinker but even that’s changed flavour. Cheers Dougie.
That is a very interesting method!
I have done it using a foot pump, but in so doing also destroyed the pump. (Twice!)