One name, two readings
本行 (Hongyō) is the Sino-Japanese reading of these kanji; as a personal name they are read Motoyuki. Matsuba (松葉, matsuba) means “pine needles”. The wazamono list of the English Wikipedia reads him Motoyuki: 本行 (Motoyuki), of Osaka, equal to 松葉本行 (Matsuba Motoyuki) and equal to 河内守本行 (Kawachi no Kami Motoyuki). The Japanese Wikipedia gives the same equivalence.
The Saga studies
The journal of the Saga Prefectural Library devoted three articles to him: 「名刀工松葉本行」 (probable reading: Meitōkō Matsuba Hongyō), by Inatomi Masao, in issue 10 (1964), and 「刀工松葉本行」 (probable reading: Tōkō Matsuba Hongyō), by Narasaki Katsutoshi, in two parts, in issues 19 (1966) and 20 (1967). Saga is the old Hizen: the articles suggest that he worked there.
What is not on record
His dates, where he was born, whom he learned from, when he received the title of Kawachi no Kami and where he worked are not recorded in any of the sources consulted. The Saga articles are the place to look for it.
Images
The same tsuba, from the other side. Tokyo National Museum, via ColBase · ColBase terms of use · source