This is interesting
I live nearby and used them for last 15 years. I always take my seed list in and collect seeds, yet they never said anything to me about closing and have had chats to them while there about their age and how much work it entailed through out the year. The company was basically a couple working out of a shed at the bottom of their garden.
I have had problems with some of their seed in last 2 years and was going to go else where for next year. This probably answers why, they may have used old seed