While Harris Angling and E.T. gave soft 7 strand a lease of life after Pegley Davies, I can only think their supply source must have stopped producing it?
Whenever I am after something niche, I make it a 'saved search' on eBay and wait it out. Something usually turns up, but it can take a while.
Might be worth searching for stranded 'Alasticum' wire too?
Spinners, spoons, plugs, jerkbaits... there's lots to talk about in this forum.