The museum is mildly interesting with some interesting titbits such as the Mopses, King Gustav's sword and a lethal punch recipe but the tour is something else. The whole building is a shrine to Art Deco, there are some photos of the peace shrine here but they don't do it justice, and don't show the Grand Temple. There's a photo of that here which misses out the glorious mosaic in the ceiling and somehow manages to make the place look, quite frankly, drab. So, if you've got an hour or so to spare it is seriously worth a visit, and it's free!
Also, have a look at the rest of the website where I grabbed the photo of the Grand Temple. It's a conspiracy theorists delight.