Actually folks it looks more to me like a "Team-Miyata" than a "Pro-Miyata",
that is if you can equate it to what was sold here in the USA.It is very similar to the "Team-Miyata" of about 1980/81 vintage.Possibly a bit newer judging by the seat stays.
I bought new and still have the lesser "Pro-Miyata"from this time frame.
It came with mostly 600ax and Dura Ace ex derailleurs.Plus it has Dia Compe Royal Gran Compe sidepulls.
Sincerely,Harris Spracher.Waynesboro Va.