Translation and Possible History for WWII Sword from Hizen province during the Edo period

[GOT]

Hello everyone,I am seeking help translating the full signature (mei) on the metal tang (nakago) of a Japanese sword brought back by my uncle from either Iwo Jima or Okinawa during WWII. It appears to be an ancestral heirloom blade carried in wartime fittings.From what I can tell so far, the signature begins with 肥前国住 (Hizen no Kuni Ju...), indicating it was made by a resident blacksmith in the famous Hizen province during the Edo period.I would deeply appreciate it if someone could help me translate the remaining characters on the far right of the peg hole to identify the specific swordsmith or generation. I am also curious if anyone can share insights regarding the cloud-motif iron handguard (tsuba). My goal is to return it to the family if they can be identified. Thanks! 

[Ray Singer]

The mei is: Hizen (no) kuni Yoshitsugu (肥前国吉次). 

Per Markus Sesko's compendium, there were two smiths who signed this way:

• YOSHITSUGU (吉次), Kan´ei (寛永, 1624-1644)
• YOSHITSUGU (吉次), Keiō (慶応, 1865-1868)