As a lurker here I thought I might of gleaned some of the basics of understanding tsuba manufacture, but how I was wrong.
I recently acquired one for a song. The patina seemed ok so I though, "What the heck." Seemingly unremarkable, under a jeweler's monocle at 40x magnification it became to clear to me just how skilled the people who manufactured these objects were/are. It's maru gata with kozuka hitsu ana, an unsigned, worn flat disc of iron about 68mm in diameter about 2mm thick and has the most amazingly detailed inlays I could to have ever imagined - a mixture of gold and brass on one side and silver on the other, it seems to me. I shall endeavour to post some pictures when in daylight again tomorrow and hope I can do this object some justice. And hope you experts might be able to enlighten me as it's origin. I have searched some sources but remain utterly clueless as to where, when and by whom it could have been made.
Until then I wish to thank you all for sharing your knowledge so freely and passing the bug onto me.