I acquired one of those unchromed bolts a few years ago, but I'm figuring on living to around 96, so I'd say if Schmisser doesn't sell his to you, remind me in about 30 years if you're still interested in buying one.
They're certainly an uncommon find, and I'll be keeping mine for a while. I have it next to the extractor tool/small parts boxes, medium sized small parts boxes, the deckungswinkelmessers, the lafette tools, ruptured case extractors, muzzle booster soaking jars, sulfur containers, recoil spring storage tubes for the 42 and 34, and a few other little accessories. A really tough item to find is the little sheet metal device that holds the bolt together while it is in the tool pouch.
(CAUTION: Explicit gun porn is shown below.)
Click the picture to enlarge.