.833" is also the same size as 21.1mm ID. That may make your search a little easier.
Fred Durrette is
> looking for a stem with a .833 diameter to fit an old
> Windsor Carrera bicycle.
That is also the size Schwinn (among other American brands) used on many models including Varsity, Continental, Super Sports and Super Tourer. The latter models came with a nice GB (British made) alloy stem, with an S forged into the side where the GB would normally be - look for one of those. I find 'em in bikeshop junk bins now and then, in the length range you mentioned.