I've acquired a nice chromed straight-blade fork with a 1-inch threaded steerer. I planned to use it on my Wheeler Chiostra of early 90's vintage. The steerer, though, is a few threads too short for me to get good purchase on it with the locknut of the existing Shimano 105 cartridge-bearing headset. With the headset adjusted and a keyed washer in place, the end of the steerer sits flush with the top of the washer.
Normal advice, I know, woulld be to get a headset with less stack height. But at 37.5mm, the 105 is already one of the shortest I'm aware of. I'm wondering whether I could use a threaded-to-threadless stem adapater (photo below) that would sit down on the keyed washer and serve essentially the same purpose as the top locknut on a threaded headset. Obviously, I'd also have to use an ugly threadless stem, but I already have a couple of those in my parts box.
Alternatively, does anyone know a good headset with stack height much shorter than 37.5mm? The only one I've found so far is the Tange Passage that Jenson USA sells for about $9. I'm not eager to replace the headset in the first place - though I can imagine that the sight of a threadless stem on my Wheeler might give me incentive - and I'm a bit leery of replacing it with something that might soon need to be replaced again.