I've had half a dozen or so of those over the years, only one as I remember had a good stock. I pulled two out of the China import material, one was about 8 numbers from a late Tokyo I had. It's too bad us old timers can't transfer the knowledge we have today back to when we were grasshoppers and Arisakas were a drug on the market.
Wonder if there was any a$$ chewing for the serial number overlap between Tokyo and Nagoya? I'd guess that was the reason for the adoption of the series designations?