Documentary images — company attribution uncertain

The flag comes from a 1902 chart republished in Fune to Hata in 1994. Alan Watt supplied a 1901 funnel reference and mentioned a flag for Nakai Hakuai, but the relationship is unclear. He also advised the separated company-name form rather than Suehirogumi.

Meaning of Nakai Hakuai and exact flag user unknown.