My 1987 Miyata One Twelve mixte has a sticker that says triple butted chromo tubes & "manga light" fork. It was Miyata "Sports Touring" lineup (the One Hundred was the other). It has brazed on downtube shifters though & originally had drop bars, & 27" wheels.

I'm in the process of giving mine (22") a makeover - made 700c wheels using original hubs. Anyhow I don't know how much it weighs but I like it. Also took a triple/6-speed mountain freewheel & accompanying derailleurs off an '87 Miyata mtb., obtained a longer bb spindle and now my One Twelve resembled one of Miyata's dedicated tourers. Has full Shimano lineup on it.