Update - Andrew answered my email, but couldn't help as the bike pre-dated his experience with 3Rensho:
That's a bit before I met him, likely 1979, 78 ish. Some details ( gear wires in downtube, end treatment) are of his style then and I assume the full Maeda Suntour motif extends to the Tange BB shell rather than Eisho Ohtsuya. Tange and Maeda are southern, from Osaka, not Konno's northern Tokyo base.
Some other useful details I was able to dredge up were that the fork crown is extremely rare for a Rensho. However, it's similar to Cherubim's crowns of the later 1970s. I found two low-res catalog scans from Cherubim and it looks like it might be a Bocama (BCM) crown. The show bike's crown is a little different, but it could have been customized.
Also, this early Rensho Cyclone has the same fork, but not the internal routing. It's also a full Suntour Superbe build. Doesn't have the same logo type, though.
