Dirtdrop knows whereof he speaks, and yes, he's a talented improvisor. Follow his links to the photos of his bikes.
There's a benefit to using stuff that once was common and now is considered obsolete: it's easy to find and not very desireable. Everyone made me think swapping out my old cottered crank bb on the Raleigh Grand Prix was going to be hellish (and Sheldon Brown's website also made it sound so) but my lbs did it without even mentioning any difficulties.
BTW, while a fixie really demands a perfect chainline and some secure lockring/locktite-suicide hub issue, converting to a ss isn't nearly as demanding--while I'd want to get a new rear wheel for a fixed, I'd have no such qualms with a ss. That's why I reiterated this point in the first place.