The upper-end Fujis back in the day were double-nutted, which made perfect sense to me, and then I didn't see any need for the spring. Unless I want a totally period-correct build, I've been using stainless hardware, with a 2.5mm-socket screw, a regular old nut, and a domed crown nut at the end. I'd rather have a milled ring i/o nut against the dropout, like the Fujis had, which are much easier to adjust by hand. But couldn't find a modern supplier. Probably just couldn't figure out the right search term for McMaster-Carr.
The stainless 2.5mm-socket screws are mega-handy not only because they won't rust, but also because driving them into the dropout with a hex wrench means my screwdriver won't be constantly slipping off the end of the screw like it does with regular slotted screws. You can also get them in several different lengths, and tailor them to any particular bike. I don't like too much screw sticking out the back, so I usually use the shortest screw that will give me the adjusting range I want for a particular dropout/frame.
Don't have any inside-slot photos handy, but on the outside of the drop they look like this:
Originally Posted by
3alarmer
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...mostly lately I don't even use springs on dropout screws. If I'm really worried about them moving around in use on a particular bike, I just double nut them on the outside. This seems to work well enough, unless you plan on repositioning them in flight.