So I cut off the greens and turned up the pot. First views looked promising.
Then I noticed the extras. I was not expecting an ants nest in there!
The compost is now back in the pot with a sprinkle of blood, fish and bone and another Pentland Javelin seed potato. This one was in the fridge from January till June 6th. It was then put in a yoghurt pot with some compost. It had about 3-inch sprouts when it went into the big pot today. I'm hoping this should give a crop in November. Wait and see!
Next pots - 410g, 620g, 360g (Average - 457.5g, a pound!)
Each pot was replanted with the saved seed potatoes.
First two "late planted" pots gave 445g between them of good quality new potatoes.