All of the Japanese made Brownings that I have seen signed K. Tsutsui have had mass produced acid etched decoration applied to them. I had always assumed that Tsutsui was either the designer of the pattern or the person responsible for the etching process.
I later learned that Kazuo Tsutsui was the chief quality control inspector. "Often considered the most important functional and structural innovations in the relationship was the hiring in 1967 of Mr. Tsutsui as chief quality manager. Tsutsui was an employee of Browning but was given the management (initially) of a seven person Miroku staff of quality control engineers at the branch office in Kochi. This arrangement continued until 1999. Mr. Tsutsui had excellent command of English in addition to his native Japanese, and had a solid understanding of the gun industry and manufacturing in general. His polite, yet powerful, leadership is why he is considered a key player in the exceptional growth of Miroku and its historic reputation for quality."
If you will post a picture of your gun, I can tell you more, especially if it is hand engraved or etched.