I found it in a Space memorabilia auction. There are 4 major Space auction houses in the US, and two of them are also well known in the coin collecting community, Heritage and Goldberg's. The quarter eagle was the first space flown gold coin I had seen come up to auction. Unfortunately, since then I've seen two others from the same spaceflight come up for auction. A couple of years ago I talked to the Commander of Gemini IV, Jim McDivitt, and he told me he also brought a $10 gold eagle along, so one of these days I suspect that will show up for auction too.
Thanks for posting the 1889's - sorry but I missed out... IHC - or - 1862 how about my favorite IHC error ?