From my search-engine slush-pile, this touched a nerve “plum jam Poland”. Somebody, presumably, was looking for it. Me too, for years.
Where I live – can’t speak for anywhere else – it’s been unavailable for years. You can still get some items from the Krakus range, though not many, and the plum jam is history.
Sainsbury’s used to do an excellent, ruby-red plum jam, which I’ve written about elsewhere here, and which was absolutely brilliant in a PBJ sandwich, and that, I think was from Poland and, like Krakus, it’s been gone for over a decade.
You can get allegedly artisanal plum jams, which tend to be more brown than red, and lack the clarity of the Polish product. They’re OK, I suppose, but they just don’t ring my bell in the same way.
Anyway, I had a rummage on Google and if you’re in the UK, I found this website, http://www.wallysdeli.co.uk/shop/agora.cgi?&product=POLISH which stocks a range of Krakus and other Polish products, including a Krakus plum spread which may be worth a look. In the real world, Wallys Deli is in Royal Arcade, Cardiff.