I don’t know much about this bike other than it is very nicely built. From the Panasonic history website, Panasonic organized a Panasonic/Shimano team in the US in 1979. I really like the fastback seatlug treatment, but I could see problems with over tightening of the seatbolt with it threading into the other seatstay. The fork has beefy round fork blades and even the seatstays are rather large.
This bike was at the Trexlertown swap meet. i assume it was for sale, but never asked a price.