This is just theory until I get a pic up here, but I have this large (9 x 8.9 cm) round iron tsuba with two hitsu-ana, and the Mei has been rubbed off almost completely. Well, except that down the right side of the Nakago-ana seppa-dai, you can make out Sendai Ju Nin.
"鉄地円形金彩大鍔 (銘仙臺住人？？) 江戸期"
with -dai written in the old Kanji. The iron is all plain, but the two hitsu ana have the remains of kin zogan round the edges on one side. Does this ring any bells? How many candidates can there be, I wonder? I have been told that the tsuba is good quality, Edo, or maybe even Muromachi. Any hints appreciated.