The California Sights were definitely intended for muzzleloaders. I think they were developed and likely manufactured by the late Andy Fautheree. As recently as last year, The Gun Works had a refurbished rifle for sale, actually just an old barrel, by Schneider of San Francisco, with what appeared to be a complete restock with a new lock and small parts, including a set of California sights. I think they were listing it as a "California Rifle." I think it finally sold. I'll see if I can recover some images.
Anyway, the California sights were not exactly like anything I know of from history, but they did have a traditional look, and I believe they were machined rather than cast. The front sight was a tall post, but very short from front to back. I believe the rear sight was sort of a semi-buckhorn, available fixed or adjustable. The adjustment mechanism was very subtle and unobtrusive.
Track of the Wolf had them years ago, and I think The Gun Works carried them, also. The California Sights were in some way connected with The House of Muskets, as well. I was looking for a set of them a little while back, and despite an extensive search, I came up dry. I'm still interested, though. Let's look again, and see what we can find.
Notchy Bob