Iron tsuba signed "Sei Issai". I could not find any information about this maker, however his work is similar to Tanaka School style. I could not find any more information about him other than that there is one more of his tsuba on sale right now. It is a tsuba with Tokubetsu Hozon tosogu sold at Touken Matsumoto:
https://www.touken-matsumoto.jp/eng/product_details_e.php?prod_no=TSU-1919
Tsuba is decorted with silver and gold nunome zogan, silver and gold inlay and gilded elements. There are many small scratches on the surface.
Made in late edo period.
Size: 68 mm x 60 mm x 4 mm