Arango Balkan Supreme is a close distance 3rd. I have a couple ounces I may press into a cake. Might make it better.
I don't really find Balkan Supreme to be anything close to Plum Pudding myself... but I think that's because I (along with many others) don't find Plum Pudding to really be a Balkan style blend in the first place. At least not in the traditional sense...
Balkans tend to have a base of Bright Virginia while leaning heavily on the Latakia and Orientals/Turkish... essentially fuller flavored English blends.
For a replacement, personally, I would focus on using Red Virginia (Probably including C&D's Red VA Cavendish), Latakia, and Perique with Orientals in backup. This is why you can see it in the color itself... PlumPud tends to have a fairly monochromatic Mahogany hue while even the richest of traditional Balkans tend to look like a multicolor confetti mix.